Surgical stapling apparatus with interlockable firing system

ABSTRACT

A surgical stapling apparatus. Various embodiments include a handle assembly that has a movable handle that is movable through actuation strokes relative to a stationary handle housing. An actuation is shaft supported at least in part within the stationary handle housing and is movable in response to manipulation of the movable handle. Various embodiments further include a firing lock out assembly that is configured to selectively prevent longitudinal movement of the actuation shaft in a distal direction. A firing release trigger is supported on the movable handle for travel therewith and is configured to interface with the firing lockout assembly to selectively release the firing lockout assembly to permit the actuation shaft to move longitudinally in the distal direction upon manipulation of the movable handle.

The following U.S. patent applications which are herein incorporated byreference are commonly owned by the Assignee of the present application:

(1) U.S. patent application entitled Surgical Stapling Apparatus WithLoad-Sensitive Firing Mechanism to Geoffrey C. Hueil et al., Docket No.END6215USNP/070332;

(2) U.S. patent application entitled Articulatable Loading Units ForSurgical Stapling and Cutting Instruments to Jerome R. Morgan et al.,Docket No. END 6218USNP/070335;

(3) U.S. patent application entitled Surgical Stapling Apparatus WithReprocessible Handle Assembly to Kevin R. Doll et al., Docket No.END6220USNP/070337;

(4) U.S. patent application entitled Surgical Stapling Apparatus WithArticulatable Components to Kevin R. Doll et al., Docket No.END6224USNP/070341;

(5) U.S. patent application entitled Surgical Stapling Apparatus WithControl Features Operable With One Hand to Steven G. Hall et al., DocketNo. END6226USNP/070343;

(6) U.S. patent application entitled Surgical Stapling Apparatus WithRetractable Firing Systems to Geoffrey C. Hueil et al., Docket No.END6227USNP/070344.

BACKGROUND Field of the Invention

The present invention relates in general to endoscopic surgicalinstruments including, but not limited to, surgical stapler instrumentsconfigured for use with disposable loading units that are capable ofapplying lines of staples to tissue while cutting the tissue betweenthose staple lines and, more particularly, to improvements relating tosuch instruments.

Endoscopic surgical instruments are often preferred over traditionalopen surgical devices since a smaller incision tends to reduce thepost-operative recovery time and complications. Consequently,significant development has gone into a range of endoscopic surgicalinstruments that are suitable for precise placement of a distal endeffector at a desired surgical site through a cannula of a trocar. Thesedistal end effectors engage the tissue in a number of ways to achieve adiagnostic or therapeutic effect (e.g., endocutter, grasper, cutter,staplers, clip applier, access device, drug/gene therapy deliverydevice, and energy device using ultrasound, RF, laser, etc.).

Known surgical staplers include an end effector that simultaneouslymakes a longitudinal incision in tissue and applies lines of staples onopposing sides of the incision. The end effector includes a pair ofcooperating jaw members that, if the instrument is intended forendoscopic or laparoscopic applications, are capable of passing througha cannula passageway. One of the jaw members receives a staple cartridgehaving at least two laterally spaced rows of staples. The other jawmember defines an anvil having staple-forming pockets aligned with therows of staples in the cartridge. The instrument commonly includes aplurality of reciprocating wedges which, when driven distally, passthrough openings in the staple cartridge and engage drivers supportingthe staples to effect the firing of the staples toward the anvil.

Different types of surgical staplers suitable for endoscopicapplications are known. For example, one type of surgical stapleremploys a staple cartridge. The staple cartridge typically supports aplurality of staples oriented on both sides of a longitudinallyextending slot in the cartridge body that is adapted to receive acutting member that is driven longitudinally therethrough. As thecutting member is driven through the cartridge slot, the staples aredriven upward into the anvil portion of the instrument. The cuttingmember may be supported on a driven member that comprises a portion ofthe instrument apart from the cartridge. Examples of those types ofdevices are described in U.S. Pat. No. 6,905,057 to Jeffrey S. Swayzeand Frederick E. Shelton, IV, entitled Surgical Stapling InstrumentIncorporating a Firing Mechanism Having a Linked Rack Transmission andU.S. Pat. No. 7,083,075 to Jeffery S. Swayze, Frederick E. Shelton, IV,Kevin Ross Doll, and Douglas B. Hoffman entitled Multi-Stroke MechanismWith Automatic End of Stroke Retractions, the disclosures of which areherein incorporated by reference in their entireties.

Other types of surgical stapling instruments are configured to operatewith disposable loading units (DLU's) that are constructed to support acartridge and knife assembly therein. Such devices that are designed toaccommodate DLU's purport to offer the advantage of a “fresh” knifeblade for each firing of the instrument. An example of such surgicalstapling instrument and DLU arrangement is disclosed in U.S. Pat. No.5,865,361 to Milliman et al., the disclosure of which is hereinincorporated by reference in its entirety.

Prior surgical stapling apparatuses, such as those disclosed in U.S.Pat. No. 5,865,361, employ firing lockout arrangements that can bedifficult to use because the clinician must depress a plunger on oneside of the handle to enable an actuation shaft to be actuated bycycling a movable handle. Such arrangement generally requires theclinician to use both hands (one to hold onto the handle assembly andactuate the movable handle and the other hand to depress the plunger).It would be more desirable to have a surgical stapling apparatus thathas a more ergonomically efficient firing lockout trigger arrangementthat does not require the clinician to use both hands to fire theinstrument.

SUMMARY

In one aspect of the invention, there is provided a surgical staplingapparatus that may include a handle assembly that may have a movablehandle and a stationary handle housing. The movable handle may bemovable through actuation strokes relative to the stationary handlehousing. An actuation shaft may be supported at least in part within thestationary handle housing and be mounted for longitudinal movement inresponse to manipulation of the movable handle through the actuationstrokes. The apparatus may further have a control rod assembly that hasa proximal end that interfaces with the actuation shaft. The control rodassembly may protrude distally from the handle housing and have a distalend that is configured to be operably attached to a disposable loadingunit. A firing lock out assembly may be supported at least in partwithin the stationary handle housing and be configured to selectivelyprevent longitudinal movement of the actuation shaft in a distaldirection. A firing release trigger may be supported on the movablehandle for travel therewith and configured to interface with the firinglockout assembly to selectively release the firing lockout assembly topermit the actuation shaft to move longitudinally in the distaldirection upon manipulation of the movable handle.

In another general aspect of various embodiments of the presentinvention, there is provided a surgical stapling apparatus that mayinclude a handle assembly that may have a movable handle and astationary handle housing. The movable handle may be movable throughactuation strokes relative to the stationary handle housing. Anelongated body may extend distally from the handle assembly and have adistal end that is adapted to releasably engage both articulating andnon-articulating disposable loading units and transmit actuation motionsthereto. An actuation member may be supported in the stationary handlehousing and be configured to apply an actuation motion to the elongatedbody in response to manipulation of the movable handle through theactuation strokes. The apparatus may further include a firing lock outassembly that is supported at least in part within the stationary handlehousing and is configured to selectively prevent longitudinal movementof the actuation shaft in a distal direction. A firing release triggermay be supported on the movable handle for travel therewith and beconfigured to interface with the firing lockout assembly to selectivelyrelease the firing lockout assembly to generate the actuation motionsupon manipulation of the movable handle.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of various embodiments of theinvention given above, and the detailed description of the embodimentsgiven below, serve to explain various principles of the presentinvention.

FIG. 1 is a perspective view of a reusable surgical stapling apparatusof various embodiments of the present invention with an articulatabledisposable loading unit coupled thereto.

FIG. 2 is a perspective view of a reusable surgical stapling apparatusof various embodiments of the present invention with a non-articulatabledisposable loading unit coupled thereto.

FIG. 3 is a partial exploded perspective view of a quick disconnectfastener embodiment of the present invention.

FIG. 4 is an exploded assembly view of a reusable surgical staplingapparatus of various embodiments of the present invention.

FIG. 5 is another exploded assembly view of the reusable surgicalstapling apparatus of FIG. 4.

FIG. 6 is an exploded assembly view of a portion of a handle assembly ofthe reusable surgical stapling apparatus embodiment of FIGS. 4 and 5.

FIG. 7 is a partial right side perspective view of a firing assemblyembodiment of the present invention.

FIG. 8 is a partial left side perspective view of the firing assemblyembodiment of FIG. 7.

FIG. 9 is a left side view of the firing assembly embodiment of FIGS. 7and 8.

FIG. 10 is an exploded assembly view of a control rod assemblyembodiment of various embodiments of the present invention.

FIG. 11 is an exploded assembly view of a rotation knob assembly andarticulation mechanism embodiment of the present invention.

FIG. 12 is a perspective view of a contaminated reusable surgicalstapling apparatus of FIGS. 1 and 2 with the disposable loading unitdetached therefrom.

FIG. 13 is a perspective view of the contaminated reusable surgicalstapling apparatus of FIG. 12 with the control rod extended out of thedistal end of the elongated body.

FIG. 14 is a diagrammatic representation of a collection of actions of acleaning method embodiment of the present invention.

FIG. 15 is a perspective view depicting the submersion of the extendedcontrol rod into a cleaning solution.

FIG. 16 is another diagrammatic representation of a collection of otheractions of a cleaning method embodiment of the present invention.

FIG. 17 is a perspective view depicting the submersion of variouscomponents of an embodiment of the present invention in a cleaningsolution.

FIG. 18 is a side view of a firing assembly embodiment of variousembodiments of the present invention.

FIG. 19 is a diagrammatic representation of a collection of actions of areassembly method embodiment of the present invention.

FIG. 20 is an exploded view depicting use of an assembly tray of anembodiment of the present invention.

FIG. 21 is a perspective view of another surgical stapling apparatus ofan embodiment of the present invention attached to a non-articulatabledisposable loading unit.

FIG. 22 is an exploded assembly view of a handle assembly of thesurgical stapling apparatus depicted in FIG. 21.

FIG. 23 is an exploded assembly view of another disposable loading unitsensing mechanism embodiment of various embodiments of the presentinvention.

FIG. 24 is an exploded assembly view of another rotation knob assemblyand articulation mechanism embodiment of the present invention.

FIG. 25 is an exploded assembly view of a firing release triggerassembly of an embodiment of the present invention.

FIG. 26 is a partial assembly view of the firing release triggerassembly depicted in FIG. 25.

FIG. 27 is an assembly view of a handle assembly embodiment of thepresent invention.

FIG. 28 is another assembly view of a handle assembly embodiment of thepresent invention with the movable handle thereof pulled against thestationary handle portion to close the anvil on the disposable loadingunit.

FIG. 29 is another assembly view of a handle assembly embodiment of thepresent invention with the movable handle returned to a startingposition after the anvil has been closed.

FIG. 30 is another assembly view of a handle assembly embodiment of thepresent invention prior to activating the firing release trigger.

FIG. 31 is another assembly view of a handle assembly embodiment of thepresent invention with the firing release trigger activated.

FIG. 32 is another assembly view of a handle assembly embodiment of thepresent invention with the firing release trigger activated and themovable handle starting to be actuated.

FIG. 33 another assembly view of a handle assembly embodiment of thepresent invention with the firing release trigger activated with themovable handle thereof pulled against the stationary handle portion.

FIG. 34 is a partial assembly view of another firing release triggerembodiment of the present invention.

FIG. 35 is a perspective view of another surgical stapling apparatusembodiment of the present invention.

FIG. 36 is a partial exploded assembly view of a portion of the handleassembly and rotatable shroud of the surgical stapling apparatus of FIG.35.

FIG. 37 is a perspective view of a portion of the surgical staplingapparatus embodiment of FIGS. 35 and 36 with a portion of the handlehousing removed to show the various components therein in the rotationmode.

FIG. 38 is a side view of the portion of the surgical stapling apparatusembodiment depicted in FIG. 36 with the selector switch thereof in adistal unlocked position.

FIG. 39 is an enlarged view of the bolt disengaged from the rotationlock ring when the apparatus is in the rotation mode.

FIG. 40 is a cross-sectional view of the surgical stapling apparatustaken along line 40-40 in FIG. 38.

FIG. 41 is a partial top view of the surgical stapling apparatus ofFIGS. 35-40 with the grip portion shown in cross-section.

FIG. 42 is a perspective view of a portion of the surgical staplingapparatus embodiment of FIGS. 35-41 with a portion of the handle housingremoved to show the various components therein in the articulation mode.

FIG. 43 is a side view of the portion of the surgical stapling apparatusembodiment depicted in FIG. 36 with the selector switch thereof in aproximal locked position.

FIG. 44 is an enlarged view of the bolt engaging the rotation lock ringto lock the apparatus in the articulation mode.

FIG. 45 is a partial cross-sectional view of the surgical staplingapparatus of FIG. 43 taken along line 45-45 in FIG. 43.

FIG. 46 is a partial cross-sectional view of a handle assembly of asurgical stapling apparatus of the present invention employing analternate translation member.

FIG. 47 is a perspective view of another surgical stapling apparatusembodiment of the present invention.

FIG. 48 is an enlarged perspective view of the handle assembly portionof the surgical stapling instrument of FIG. 47 with a portion of thehandle housing removed for clarity.

FIG. 49 is partial side view of the handle assembly depicted in FIG. 49with a portion of the handle housing removed for clarity.

FIG. 50 is a partial top view of the handle assembly depicted in FIG. 49with some components shown in cross-section and with the articulationsystem thereof in a locked position.

FIG. 51 is a partial top view of the handle assembly depicted in FIGS.49 and 50 with some components shown in cross-section and with thearticulation system thereof in an unlocked position.

FIG. 52 is a perspective view of another surgical stapling apparatusembodiment of the present invention.

FIG. 53 is a perspective assembly view of the handle assembly portion ofthe surgical stapling apparatus of FIG. 52 with a portion of the handlehousing removed and the sensor cylinder omitted for clarity.

FIG. 54 is a left-side perspective assembly view of a portion of thehandle assembly of the surgical stapling apparatus of FIGS. 52 and 53with the housing removed for clarity.

FIG. 55 is a right-side perspective assembly view of a portion of thehandle assembly of the surgical stapling apparatus of FIGS. 52-54 withthe housing removed for clarity.

FIG. 56 is a side view of a portion of the articulation system, gear andarticulation selector switch embodiments with the articulation switch ina neutral position.

FIG. 57 is another side view of the articulation system, gear andarticulation selector switch embodiments with the articulation switch inthe left articulation position.

FIG. 58 is another side view of the articulation system and gear andarticulation selector switch embodiments with the articulation switch inthe right articulation position.

FIG. 59 is a bottom view of the gear selector switch, drive gearassembly, articulation transfer gear train and actuation bar of anembodiment of the present invention with the selector gear selectorswitch in the articulation position.

FIG. 60 is a bottom view of the gear selector switch, drive gearassembly, articulation transfer gear train and actuation bar of anembodiment of the present invention with the selector gear selectorswitch in the firing position.

FIG. 61 is an enlarged view of the gear selector switch embodiment inthe articulation position.

FIG. 62 is a cross-sectional view of the gear selector switch embodimentin the firing position.

FIG. 63 is an end view of a various components of the surgical staplingapparatus in an articulation mode.

FIG. 64 is another end view of the components depicted in FIG. 63 in afiring mode.

FIG. 65 is a partial cross-sectional perspective view of an alternativearticulation mechanism embodiment of the present invention.

FIG. 66 is a partial top cross-sectional view of the articulationmechanism of FIG. 65.

FIG. 67 illustrates a position of the cam disc and articulation pin ofthe articulation mechanism embodiment of FIGS. 65 and 66 in a leftarticulated position.

FIG. 68 illustrates a position of the cam disc and articulation pin ofthe articulation mechanism embodiment of FIGS. 65 and 66 in a straight(non-articulated) position.

FIG. 69 illustrates a position of the cam disc and articulation pin ofthe articulation mechanism embodiment of FIGS. 65 and 66 in a rightarticulated position.

FIG. 70 is a cross-sectional plan view of a portion of anotherarticulation mechanism embodiment of the present invention.

FIG. 71 is a partial cross-sectional view of a portion of thearticulation mechanism embodiment of FIG. 70.

FIG. 72 is a side view of another articulation mechanism embodiment ofthe present invention with some of the components thereof shown incross-section.

FIG. 73 is a cross-sectional view of the articulation mechanismembodiment of FIG. 72 taken along line 73-73 in FIG. 72.

FIG. 74 is a side view of another articulation mechanism embodiment ofthe present invention with some of the components thereof shown incross-section.

FIG. 75 is a perspective view of an outer articulation ring embodimentof the articulation mechanism of FIG. 74.

FIG. 76 is a left side perspective view of another surgical staplingapparatus embodiment of the present invention.

FIG. 77 is a right side perspective view of the surgical staplingapparatus embodiment depicted in FIG. 76.

FIG. 78 is an exploded assembly view of the right housing segment of thehandle assembly with the removable cover detached from the housingsegment.

FIG. 79 is another view of the right housing segment of the handleassembly with the removable cover detached from the housing segment.

FIG. 80 is a right side view of the handle assembly of the surgicalstapling apparatus depicted in FIGS. 76-78.

FIG. 81 is a cross-sectional view of the housing assembly taken alongline 81-81 in FIG. 80.

FIG. 82 is a cross-sectional view of the housing assembly taken alongline 82-82 in FIG. 80.

FIG. 83 is a cross-sectional view of a portion of the housing assemblyand cocking knob taken along line 83-83 in FIG. 80.

FIG. 84 is a right side view of the handle assembly of the surgicalstapling apparatus depicted in FIGS. 76-83 with the removable coverremoved to show the retract knob and the cocking knob in the “pre-fired”position.

FIG. 85 is another right side view of the handle assembly of FIG. 84with the cocking knob in a cocked position.

FIG. 86 is another right side view of the handle assembly of FIGS. 84and 85 showing the position of the retract knob and the cocking knobprior to reaching the fully fired position.

FIG. 87 is a partial cross-sectional view of the handle assembly andcocking knob with the cocking knob biased in a clockwise direction torelease the lock member.

FIG. 88 is another partial cross-sectional view of the handle assembly,cocking knob and retract knob wherein the retract knob has released thelock member to permit the actuation shaft to be automatically retracted.

FIG. 89 is a partial perspective view of a portion of a disposableloading unit of various embodiments of the present invention.

FIG. 90 is a perspective view of a pawl embodiment of variousembodiments of the present invention.

FIG. 91 is a perspective view of another pawl embodiment of variousembodiments of the present invention.

FIG. 92 is a bottom perspective view of an actuation shaft embodiment ofvarious embodiments of the present invention.

FIG. 93 is a bottom perspective view of another actuation shaftembodiment of various embodiments of the present invention.

FIG. 93A is a side view of a portion of a firing system embodiment ofthe present invention used in connection with a surgical staplinginstrument of the type disclosed in U.S. patent application Ser. No.11/821,277 with the tooth in driving engagement with the firing member.

FIG. 93B is another side view of the firing system embodiment of FIG.93A with the tooth in the disengaged position.

FIG. 94 is a perspective view of a surgical stapling apparatus and adisposable loading unit embodiment of the present invention.

FIG. 95 is a perspective view of the disposable loading unit embodimentdepicted in FIG. 94.

FIG. 96 is an exploded assembly view of the disposable loading unitembodiment of FIG. 95.

FIG. 97 is a perspective view of the disposable loading unit of FIGS. 95and 96 being articulated with a pair of surgical graspers.

FIG. 98 is a perspective view of another disposable loading unitembodiment of the present invention.

FIG. 99 is an exploded assembly view of the disposable loading unitembodiment of FIG. 98.

FIG. 100 is a perspective view of the disposable loading unit of FIGS.98 and 99 being articulated with a pair of surgical graspers.

FIG. 101 is a perspective view of the disposable loading unit of FIGS.98-100 illustrating passive articulation travel and active articulationtravel thereof.

FIG. 102 is a perspective view of another disposable loading unitembodiment of the present invention.

FIG. 103 is an exploded assembly view of the disposable loading unitembodiment of FIG. 102.

FIG. 104 is an exploded assembly view of another disposable loading unitsensing mechanism and control rod assembly embodiment of variousembodiments of the present invention.

FIG. 105 is a perspective view of another disposable loading unitembodiment of the present invention illustrating passive articulationtravel and active articulation travel thereof.

FIG. 106 is an exploded assembly view of the disposable loading unit ofFIG. 105.

FIG. 107 is a proximal end view of the disposable loading unit of FIGS.105 and 106 taken in the direction represented by arrows 107-107 in FIG.105.

FIG. 108 is a perspective view of another surgical stapling apparatusembodiment of the present invention.

FIG. 109 is an exploded assembly view of an articulation systemembodiment of the present invention employed in the surgical staplingapparatus of FIG. 108.

FIG. 110 is an exploded assembly view of portions of the intermediatearticulation joint of the articulation system of FIG. 109.

FIG. 11 is a perspective of the surgical stapling apparatus of FIG. 108employed in an open surgical application.

FIG. 112 is a perspective view of another surgical stapling apparatusembodiment of the present invention employed in connection with aconventional trocar to perform an endoscopic surgical procedure.

FIG. 113 is a perspective view of another articulation system embodimentof the present invention.

FIG. 114 is a partial exploded assembly view of the articulation systemof FIG. 113.

FIG. 115 is a side assembly view of the articulation system of FIGS. 113and 114.

FIG. 116 is a perspective view of another articulation system embodimentof the present invention.

FIG. 117 is a perspective view of another articulation system embodimentof the present invention.

FIG. 118 is an exploded assembly view of the articulation system of FIG.117.

FIG. 119 is a side assembly view of a portion of the articulation systemof FIGS. 117 and 118 with some components thereof shown in cross-sectionfor clarity.

FIG. 120 is a partial perspective assembly view of various articulationbar and pin embodiments of the present invention.

FIG. 121 is a cross-sectional view of the articulation bar and pinembodiments depicted in FIG. 120.

FIG. 122 is a perspective view of another surgical stapling apparatusembodiment of the present invention employed in connection with aconventional trocar to perform an endoscopic surgical procedure.

FIG. 123 is an exploded partial assembly view of an articulation systemembodiment of the surgical stapling apparatus of FIG. 122.

DETAILED DESCRIPTION

Turning to the Drawings, wherein like numerals denote like componentsthroughout the several views, FIG. 1 depicts a reusable surgicalinstrument, which in the illustrative versions is more particularly asurgical stapling apparatus 10, capable of practicing the uniquebenefits of various embodiments of the present invention. The surgicalstapling apparatus 10 may include a handle assembly 12 and an elongatedbody 14. FIG. 1 illustrates surgical stapling apparatus 10 with anarticulatable disposable loading unit 16 coupled thereto. FIG. 2illustrates surgical stapling apparatus 10 with a non-articulatingdisposable loading unit 16′ coupled thereto. The disposable loadingunits 16, 16′ may include a tool assembly 17 that includes a cartridgeassembly 18 that houses a plurality of surgical staples therein. Thetool assembly 17 may further include a staple-forming anvil 20. Suchdisposable loading units 16, 16′ may perform surgical procedures such ascutting tissue and applying staples on each side of the cut. Variousembodiments of the present invention may be used in connection with thedisposable loading units disclosed in U.S. Pat. No. 5,865,361 toMilliman et al., the disclosure of which is herein incorporated byreference.

It will be appreciated that the terms “proximal” and “distal” are usedherein with reference to a clinician gripping the handle assembly of aninstrument. Thus, the tool assembly 17 is distal with respect to themore proximal handle assembly 12. It will be further appreciated that,for convenience and clarity, spatial terms such as “vertical”,“horizontal”, “up”, “down”, “right”, and “left” are used herein withrespect to the drawings. However, surgical instruments are used in manyorientations and positions, and these terms are not intended to belimiting and absolute.

As was discussed above, prior surgical stapling apparatuses such asthose disclosed in U.S. Pat. No. 5,865,361 are ill-suited forreprocessing (i.e., re-sterilization) to enable the instruments to bereused because they are not easily disassembled. The surgical staplingapparatus 10 depicted in FIGS. 1-20 is adapted to be convenientlyreprocessed and can be used in connection with articulatable disposableloading units 16 (FIG. 1) and non-articulating disposable loading units16′ (FIG. 2) as will be discussed in further detail below. The variousembodiments of the surgical stapling apparatus 10 may employ a handleassembly 12 that is constructed to facilitate cleaning and sterilizationof the various components housed therein. For example, handle assembly12 may include a stationary handle portion 22, a movable handle 24, anda barrel portion 26. A rotatable knob 28 may be mounted on the forwardend of barrel portion 26 to facilitate rotation of elongated body 14with respect to handle assembly 12 about longitudinal axis “L-L” of thestapling apparatus 10. As will be discussed in further detail below,some handle assembly embodiments may also include an articulation lever30 that is mounted on the forward end of barrel portion 26 adjacentrotatable knob 28. Other embodiments may be designed to be used inconnection with non-articulatable disposable loading units and thus thehandle assembly 12 may not include such articulation components. Handleassembly 12 may further include handle housing 36, which may be formedfrom a first housing segment 36 a and a second housing segment 36 b,which, when coupled together, form handle housing 36. To facilitate easydisassembly of handle assembly 12, the housing segments 36 a, 36 b maybe coupled together with, at east one and, preferably three quickrelease fasteners 400.

As shown in FIG. 3, a quick release fastener 400 may comprise abayonet-type fastener that includes a screw head portion 402 that has abarrel or body portion 404 protruding therefrom that is sized to bereceived in a hole 412 in a corresponding stand off member 410 formed inthe housing segment 36 a. A rod or cross member 406 is mounted in thebody portion 404 to form a substantially T-shaped connector portion 408sized to be received in slot segments 414 on each side of the hole 412.The slot segments 414 are configured such that when the T-shapedconnector portion 408 is inserted into the hole 412 and slot segments414 and turned as illustrated by the arrow “T” in FIG. 3, the rod 406releasably retains the connector portion 408 in position. In variousembodiments, the body portion 404 of the quick release fastener 400 mayextend through a corresponding hole in the housing segment 36 b and thenhave the rod or cross member 406 attached thereto such that the quickrelease fastener 400 is non-removably coupled to the second housingsegment 36 b so that when the housing segment 36 b is detached from thefirst housing segment 36 a, the quick release fasteners 400 do notbecome lost and remain with the second housing segment 36 b forcleaning/sterilization purposes.

Referring to FIGS. 4-8, a movable handle 24 may be pivotably coupled toa firing assembly 500 that may be removed from the handle housing 36 forcleaning/sterilization purposes. In various embodiments, the firingassembly 500 may comprise an internal frame assembly 510 that operablysupports the movable handle 24. As can be seen in those Figures, themovable handle 24 may be pivotally attached to the internal frameassembly 510 by pivot pin 38. A biasing member 40, which may comprise atorsion spring, biases movable handle 24 away from stationary handleportion 22. See FIGS. 6-8. An actuation shaft 46 may be supported withinthe internal frame assembly 510 and may include a toothed rack 48. Adriving pawl 42 having a rack engagement tooth 43 thereon is pivotablymounted to one end of movable handle 24 about a pivot pin 44. See FIG.8. A biasing member 50, which may comprise a torsion spring, ispositioned to urge driving pawl 42 towards toothed rack 48 of actuationshaft 46. See FIG. 7. Movable handle 24 is pivotable to move rackengagement tooth 43 of driving pawl 42 into contact with toothed rack 48of actuation shaft 46 to advance the actuation shaft 46 linearly in thedistal direction “DD”. The distal end of actuation shaft 46 may have acavity 47 formed therein to receive the proximal end 49 of a control rod52 (FIG. 4) such that linear advancement of actuation shaft 46 causescorresponding linear advancement of control rod 52.

The internal frame assembly 510 may further include a locking pawl 54that has a locking protrusion 55 thereon and is pivotably coupled to theframe assembly 510 about pivot pin 57 and is biased into a cavity 512 inthe actuation shaft 46 by a biasing member 56, which may comprise atorsion spring. Locking protrusion 55 of locking pawl 54 is movable intoengagement with the cavity 512 to retain actuation shaft 46 in alongitudinally fixed position when no disposable loading unit has beencoupled to the elongated body 14 as will be discussed in further detailbelow.

The internal frame assembly 510 may also operably house a retractionmechanism 58 that may comprise a right hand retractor knob 32 a and aleft hand retractor knob 32 b that are connected to the proximal end ofactuation shaft 46 by a coupling rod 60. See FIG. 6. Coupling rod 60 mayinclude right and left engagement portions 62 a and 62 b for receivingretractor knobs 32 a and 32 b, respectively and a central portion 62Cwhich is dimensioned and configured to translate within a pair oflongitudinal slots 514 in the internal frame assembly 510 and slots 34 aformed in actuation shaft 46 adjacent the proximal end thereof. Theretractor knobs 32 a, 32 b, may each have a cavity therein to enablethem to be pressed onto the corresponding engagement portions 62 a, 62b, respectively. In various embodiments of the present invention, thecoupling rod 60 may be configured so that when the retractor knobs 32 a,32 b are removed therefrom for disassembly purposes, the coupling rod 60remains mounted in position with the internal frame assembly 510. SeeFIGS. 7, 8 and 17. As shown in FIG. 6, the central portion 62C may beprovided with a notch 63 that is adapted to be retainingly engaged by aretaining tab (not shown) formed on a proximal end of a retainer 520that is slidably received in a cavity 522 in the actuation shaft 46. Aretract spring 524 is attached between a cross post 526 in the actuationshaft 46 and the retainer 520 to pull the retainer 520 distally suchthat the retaining tab formed on the proximal end thereof retaininglyengages the notch 63 in the coupling rod 60. Those of ordinary skill inthe art will understand that when the retractor knobs 32 a, 32 b aredetached from the coupling rod 60, the coupling rod 60 remains coupledto the internal frame assembly 510 by the tab on the retainer 520.

A release plate 64 may be operatively associated with actuation shaft 46and is mounted for movement with respect thereto in response tomanipulation of retractor knobs 32 a, 32 b. A pair of spaced apart pins66 may extend outwardly from a lateral face of actuation shaft 46 toengage a pair of corresponding angled cam slots 68 formed in releaseplate 64. Upon movement of retractor knobs 32 a, 32 b in the proximaldirection “PD”, pins 66 can release the release plate 64 downwardly withrespect to actuation shaft 46 and with respect to toothed rack 48 suchthat the bottom portion of release plate 64 extends below toothed rack48 to disengage rack engagement tooth 43 of driving pawl 42 from toothedrack 48. A transverse slot 70 is formed at the proximal end of releaseplate 64 to accommodate the central portion 62 c of coupling rod 60, andelongated slots 34 (FIG. 1) are defined in the barrel section 26 ofhandle assembly 12 to accommodate the longitudinal translation ofcoupling rod 60 as retraction knobs 32 a, 32 b are pulled in theproximal direction “PD” to retract actuation shaft 46 and thus retractcontrol rod 52 in the proximal direction “PD”.

In various embodiments, the internal frame assembly 510 may alsooperably support a firing lockout assembly 80 which may include aplunger 82 and a pivotable locking member 83. See FIGS. 7 and 8. Plunger82 is biased to a central position by biasing springs 84 and includesannular tapered camming surfaces 85. Each end of plunger 82 extendsthrough handle housing 36 adjacent an upper end of stationary handleportion 22. Pivotable locking member 83 may be pivotably attached at itsdistal end about pivot pin 86 and may include a locking gate 88 andproximal extension 90 having a slot 89 formed therein. See FIGS. 7 and8. Pivotable locking member 83 may be biased by a spring 93 (FIG. 9) tocause the locking gate 88 attached thereto to enter into a lockingdetent 53 in the bottom of the actuation shaft 46 to prevent advancementof actuation shaft 46 and subsequent firing of stapling apparatus 10.Annular tapered camming surface 85 on plunger 82 is positioned to extendinto tapered slot 89 in proximal extension 90. Lateral movement ofplunger 82 in either direction against the bias of either spring 84moves tapered camming surface 85 into engagement with the sidewalls ofthe tapered slot 89 in the proximal extension 90 to pivot pivotablelocking member 83 about pivot pin 86 to move locking gate 88 out of thelocking detent 53 to permit advancement of actuation shaft 46.

As can be further seen in FIGS. 6-9, a sensor link 182 may also beoperably supported by the internal frame assembly 510. As can be seen inthose Figures, the sensor link 182 may be slidably attached to theinternal frame assembly 510 by a pin or screw 530 that extends through aslot 532 in the sensor link 182 such that the sensor link 182 may slidelongitudinally relative to the internal frame assembly 510. A distal endof a spring 531 may be attached to the screw 530 and the proximal end ofthe spring 531 may be hooked over a hook 533 on the sensor link 182. SeeFIG. 6. Spring 531 serves to bias the sensor link 182 in the distaldirection “DD”. The sensor link 182 may further include a proximallocking arm 535 that has an inwardly protruding proximal end 537configured to interact with the locking pawl 54. In particular, when nodisposable loading unit 16, 16′ is attached to the stapling apparatus10, the sensor link 182 is biased distally by spring 531. When in that“unloaded” position, the proximal end 537 of the proximal locking arm535 disengages the locking pawl 54 to retain the locking pawl 54 in thelocked position wherein the locking protrusion 55 is received in cavity512 to retain actuation shaft 46 in a longitudinally fixed position.Thus, when no disposable loading unit 16, 16′ is coupled to the surgicalstapling apparatus 10, the stapling apparatus 10 cannot normally befired.

The sensor link 182 may further have a downwardly extending distal tab534 formed thereon for contact with a flange 179 formed on a sensorcylinder 178. See FIGS. 4 and 5. As will be discussed in further detailbelow, a sensor tube 176 is oriented to interface with the sensorcylinder 178. See FIG. 10. Sensor link 182 may further have a spring arm536 with a downwardly extending end 538 which engages a camming surface83 a on pivotable locking member 83. See FIG. 7. When a disposableloading unit 16, 16′ is coupled to the distal end of elongated body 14,the disposable loading unit 16, 16′ engages the distal end of the sensortube 176 to drive sensor tube 176 proximally, and thereby drive sensorcylinder 178 and sensor link 182 proximally. Movement of sensor link 182proximally causes end 538 of spring arm 536 to move proximally ofcamming surface 83 a to allow locking member 83 to pivot under the biasof a spring 92 from a position permitting firing of stapling apparatus10 (i.e., permit the actuation of actuation shaft 46) to a blockingposition, wherein the locking gate 88 is received in the locking detent53 in actuation shaft 46 and prevent firing of stapling apparatus 10.Sensor link 182 prevents firing when a disposable loading unit 16 isabsent. Locking member 83 prevents firing when closing and opening theanvil assembly 20. Also, as the sensor link 182 is moved proximally, theproximal end 537 of the proximal locking arm 535 serves to pivot thelocking pawl 54 such that the locking protrusion 55 moves out of cavity512 to permit actuation shaft 46 to be actuated. See FIG. 8.

As shown in FIG. 4, the handle housing 36 may include an annular channel117 configured to receive an annular rib 118 formed on the proximal endof rotation knob 28, which is preferably formed from moldedhalf-sections 28 a and 28 b that may be interconnected by screws 29.Annular channel 117 and rib 118 permit relative rotation betweenrotation knob 28 and handle housing 36. As illustrated in FIG. 4,elongated body 14 may include an outer casing 124 that is sized tosupport a sensor tube 176 (shown in FIG. 10) and articulation link 123.Such assembly of components 123, 124, 176, and 52 is, at times referredto herein as a “control rod assembly 125”, and may include othercomponents journaled on the control rod 52. The proximal end of casing124 includes diametrically opposed openings 128, which are dimensionedto receive radial projections 132 formed on the distal end of rotationknob 28. See FIGS. 4 and 5. Projections 132 and openings 128 fixedlysecure rotation knob 28 and elongated body 14 in relation to each other,both longitudinally and rotatably. Rotation of rotation knob 28 withrespect to handle assembly 12 thus results in corresponding rotation ofelongated body 14 about longitudinal axis L-L with respect to handleassembly 12. It will also be appreciated that because the disposableloading unit 16, 16′ is coupled to the distal end of the elongated body14, rotation of the elongated body 14 also results in the rotation ofthe disposable loading unit 16, 16′.

In various embodiments, an articulation mechanism 120 may be supportedon rotatable knob 28 and include an articulation lever 30 and a cammember 136. See FIG. 11. Articulation lever 30 may be pivotably mountedabout pivot pin 140 which may be threadedly attached to rotation knob28. A shifting pin 142 may be received in a socket 131 in the bottom ofarticulation lever 30 and extend downwardly therefrom for engagementwith cam member 136. Cam member 136 may include a housing 144 that hasan elongated slot 146 extending through one side thereof. A pair ofcamming plates 136 a, 136 b may be coupled to housing 144 by a pair ofrivets 145 or other suitable fasteners to form a camming plate assembly137. In other embodiments, the camming plate assembly 137 may beintegrally formed with the housing 144. The camming plates 136 a and 136b may have a stepped camming surface 148 a, 148 b, respectively thatform a stepped camming surface 148. Each step of camming surface 148corresponds to a particular degree of articulation of stapling apparatus10. Elongated slot 146 is configured to receive shifting pin 142protruding from articulation lever 30. Camming plate assembly 137 isattached to housing 144 in such a manner so as to form a distal steppedportion 150 and a proximal stepped portion 152. Proximal stepped portion152 includes a recess 154.

As can be seen in FIG. 4, the articulation mechanism 120 may furtherinclude a translation member 138 that has an upstanding arm portion 540that has a notch 542 therein that is sized to receive a tab 544 formedon the sensor cylinder 178. The distal end of translation member 138 mayinclude an arm 546 which includes an opening 548 configured to receive afinger 164 extending from the proximal end of articulation link 123. SeeFIGS. 4 and 10. A pin 166 that may be constructed from a non-abrasivematerial, e.g., Teflon®, is secured to translation member 138 anddimensioned to be received within stepped camming surface 148. In anassembled condition, distal and proximal stepped portions 150 and 152 ofcam member 136 are positioned beneath flanges 170 and 172 formed onrotation knob 28 to restrict cam member 136 to transverse movement withrespect to the longitudinal axis “L-L” of stapling apparatus 10. Whenarticulation lever 30 is pivoted about pivot pin 140, cam member 136 ismoved transversely on rotation knob 28 to move stepped camming surface148 transversely relative to pin 166, forcing pin 166 to move proximallyor distally along stepped camming surface 148. Since pin 166 is fixedlyattached to translation member 138, translation member 138 is movedproximally or distally to effect corresponding proximal or distalmovement of the articulation link 123.

The sensor cylinder 178 may have a nub portion 544 configured to bereceived within recess 154 in the camming plate assembly 137. When anarticulating disposable loading unit 16 is operably coupled to thedistal end of elongated body 14 of stapling apparatus 10, the nub 544moves proximally of recess 154 in cam member 136. With nub 544positioned proximally of recess 154, cam member 136 is free to movetransversely to effect articulation of stapling apparatus 10. Asexplained in U.S. Pat. No. 5,865,361, a non-articulating disposableloading unit 16′ does not have an extended insertion tip. As such, whena non-articulating disposable loading unit 16′ is inserted in elongatedbody 14, sensor cylinder 178 is not moved proximally a sufficientdistance to move nub 544 from recess 154. Thus, cam member 136 isprevented from moving transversely by nub 544 which is positioned inrecess 154 and articulation lever 30 is locked in its central position.

As can be seen in FIGS. 4-9, this embodiment may also include a firinglockout override assembly 600 that has an override button 601 that hasan override wire 602 attached thereto. The override wire 602 may beslidably supported within wire form retention tabs 606 formed on the topsurface 604 of the internal frame assembly 510. A distal end 610 of theoverride wire 602 is mounted in a hole 539 in the distal end of thesensor link 182. When the override button 601 is moved in the proximaldirection “PD”, the override wire 602 pulls the sensor link 182proximally which biases the locking pawl 54 out of locking engagementwith the actuation shaft 46 and also causes end 538 of spring arm 536 tomove proximally of camming surface 83 a to allow locking member 83 topivot under the bias of spring 92 from a position permitting firing ofstapling apparatus 10 (i.e., permit the actuation of actuation shaft 46)to a blocking position, wherein the locking gate 88 is received in thelocking detent 53 in actuation shaft 46 and prevents firing of staplingapparatus 10 unless the plunger 82 is depressed.

Referring to FIGS. 1, 2, 9 and 10, to use stapling apparatus 10, adisposable loading unit 16, 16′ is first secured to the distal end ofelongated body 14. The stapling apparatus 10 can be used witharticulatable disposable loading units 16 and non-articulatabledisposable loading units 16′ that each have, for example, linear rows ofstaples between about 30 mm and about 60 mm. A method of coupling adisposable loading unit 16, 16′ to elongated body 14 is disclosed inU.S. Pat. No. 5,865,361. When the insertion tip of the disposableloading unit 16, 16′ engages the distal end of sensor tube 176, thedisposable loading unit sensing mechanism is actuated. As the insertiontip engages and moves sensor tube 176 proximally, the sensor tube 176effects proximal movement of sensor cylinder 178 and sensor link 182 inthe proximal “PD” direction to pivot locking member 83counter-clockwise, from a non-blocking position to a position whereingate 88 blocks movement of actuation shaft 46.

When a disposable loading unit 16, 16′ is coupled to stapling apparatus10, tool assembly 17 can be positioned about a target tissue. To clampthe target tissue between the staple forming anvil 20 and cartridgeassembly 18, movable handle 24 is pivoted toward the stationary handleportion 22 against the bias of torsion spring 40 to move driving pawl 42into engagement with a shoulder 322 on actuation shaft 46. Engagementbetween shoulder 322 and driving pawl 42 advances actuation shaft 46distally and thus advances control rod 52 distally. Control rod 52 isconnected at its distal end to the axial drive assembly in thedisposable loading unit 16, 16′, including the drive beam therein, suchthat distal movement of control rod 52 effects distal movement of thedrive beam in the distal direction to thereby cause the staple forminganvil 20 to pivot closed in the manner described in U.S. Pat. No.5,865,361. In various embodiments, one complete stroke of movable handle24 may advance actuation shaft 46 approximately 15 mm which may besufficient to clamp tissue during the first stroke but not to firestaples. The actuation shaft 46 is maintained in its longitudinalposition after the movable handle 24 is released by the locking gate 88which is biased into the detent 53 in the bottom of the actuation shaft46. Upon release of movable handle 24, drive pawl 42 moves over rack 48as torsion spring 40 returns handle 24 to a position spaced fromstationary handle 22. In this position, driving pawl 42 is urged intoengagement with toothed rack 48 to further retain actuation shaft 46 inits longitudinal fixed position.

To “fire” the staples supported within the cartridge assembly 18 (i.e.,drive the staples into the staple forming anvil 20), movable handle 24is actuated again. In various embodiments, the stapling apparatus 10 maybe capable of receiving disposable loading units 16, 16′ having linearrows of staples of between about 30 mm and about 60 mm. In sucharrangements, the stapling apparatus 10 may be configured such that eachstroke of the movable handle 24 advances actuation shaft 46 15 mm.Because one stroke is required to clamp tissue, the movable handle 24must be actuated (n+1) strokes to fire staples, where n is the length ofthe linear rows of staples in the disposable loading unit attached tothe stapling apparatus 10 divided by 15 mm.

Before the staples may be fired, firing lockout assembly 80 must beactuated to move locking gate 88 from its blocking position to anon-blocking position. This may be accomplished by activating plunger 82to cause camming surface 85 to engage the sidewalls of slot 89 oflocking member 83 and thereby pivot locking member 83 in thecounterclockwise direction in FIG. 9. Thereafter, movable handle 24 maybe actuated an appropriate number of strokes to advance actuation shaft46, and thus control rod 52 and drive beam in the distal direction “DD”to fire the disposable loading unit 16, 16′ in a known manner. Toretract actuation shaft 46 and thus control rod 52 and the drive memberof the disposable loading unit 16, 16′ after firing staples, retractionknobs 32 a, 32 b may be pulled proximally causing pins 66 to moverelease plate 64 in the direction indicated by arrow “J” in FIG. 7 overteeth 49 to disengage drive pawl 42 from engagement with teeth 49 of thetoothed rack 48.

Those of ordinary skill in the art will understand that the disposableloading units 16, 16′ are sterilized and packaged in sterile packagingmaterials prior to use. Likewise, the stapling apparatus 10 is alsosterilized prior to use. After the disposable loading unit 16, 16′ isused, it is discarded. While the stapling apparatus 10 could alsoconceivably be re-sterilized for additional uses, those priorinstruments such as those described in the aforementioned U.S. Pat. No.5,865,361 and other known instruments adapted for use with disposableloading units are not well-suited for easy disassembly to facilitatesterilization of their various internal components. Consequently, suchunits are often disposed of after a single use. As will be furtherexplained below, the stapling apparatus 10 is constructed to facilitateeasy disassembly to permit the stapling apparatus 10 to be reprocessed(i.e., re-sterilized).

FIG. 12 depicts the stapling apparatus 10 after it has been used and thedisposable loading unit (not shown) has been decoupled therefrom (action700 in FIG. 14). The stippling 620, 622 represents exemplary areas ofcontamination on the elongated body 14 and the handle assembly 12,respectively. To begin the reprocessing of the stapling apparatus 10,the user moves the firing override button 601 proximally and holds theoverride button 601 in that proximal position (action 702). Such actionmoves the sensor link 182 proximally in the above-described manner andpermits the user to actuate the actuation shaft 46. The user also movesthe plunger 82 to enable the movable handle 24 to be cycled to actuatethe actuation shaft 46. The user may then repeatedly cycle the movablehandle 24 (represented by arrow “R” in FIG. 13) to extend the controlrod 52 such that the contaminated portion 624 of the control rod 52extends out of the casing 124 (action 704). See FIG. 13. The user maythen insert the exposed contaminated portion 624 of the control rod 52and the distal end of the casing 124 into an appropriate cleaning orsterilization medium 630 such as, for example, Ethylene Oxide, Peroxide,etc. (action 706). See FIG. 15.

To sterilize the handle assembly 12, the handle assembly 12 may beeasily disassembled (action 708). Referring again to FIG. 5, the usermay separate the rotation knob segments 28 a and 28 b by removing thescrews or fasteners 29 (action 710). The rotation knob segments 28 a and28 b, as well as the translation member 138, are removed and laid aside(action 712). The right and left retract knobs 32 a, 32 b are thenpulled off of the coupling rod 60 (action 714). The three quick releasefasteners 400 may then be removed from the left hand housing portion 36b—unless the fasteners 400 are loosely coupled thereto (action 716). Thehandle housing segment 36 b may then be laid aside (action 718). Theuser may then lift the firing assembly 500 from the housing segment 36 aand place it on a flat surface (action 720). The user may then grasp thedistal end of the control rod 52 and rotate it vertically (representedby arrow “V” in FIG. 5—action 722). The control rod 52 may then bepulled from the cavity 47 in the actuation shaft 46 as shown in FIG. 4(action 724). The user may then detach the sensor cylinder 178 from theproximal end of the sensor tube 176 (action 726). Thus, the staplingapparatus 10 may be separated into the parts shown in FIG. 4. The usermay then select a desired cleaning/sterilization cycle (action 730). SeeFIG. 16. In particular, the user may choose between a “wet” cleaningcycle wherein the components are submerged in an appropriate cleaningsolution 630 (FIG. 17) or a “dry” cleaning cycle wherein radiation isemployed or a combination of both cycles may be employed. Those ofordinary skill in the art will recognize that FIG. 17 only illustratessome of the handle assembly components being submerged in the cleaningmedium 630. It will be appreciated that it is intended that all of thehandle assembly components be submerged either simultaneously (if thecontainer is large enough) or one at a time or in small groups until allof the components have been cleaned (action 732). It will beappreciated, however, those components that have been worn or damagedmay be replaced with new sterilized components to complete the assembly.The reservoir 632 containing the cleaning medium 630 may be agitated orthe cleaning medium may be stirred or otherwise agitated usingconventional methods to drive the cleaning medium 630 through theopenings 511 in the internal frame assembly 510 into contact with all ofthe components retained therein (action 734). After the components haveall been exposed to the cleaning medium 630 for a desired amount oftime, the components may be removed from the cleaning medium 630 andthen air dried or dried utilizing other conventional methods (action736).

After the components have been cleaned by the cleaning medium (actions732-736), the user may also choose to irradiate the components (actions740, 742) or the user may elect not to irradiate the components (action744) at which point the user then may lubricate certain components(action 746) as will be discussed in further detail below. If the userelects to irradiate the disassembled components either after wetcleaning the components or in lieu of wet cleaning, the user may lay allof the component parts on an appropriate tray or other object (notshown). Radiation may then be applied to the components using conventionirradiation techniques. For example, electron beam radiation may beemployed. Other forms of vapor sterilization mediums, such as forexample, Ethylene Oxide vapor mediums, Peroxide vapor mediums may alsobe employed.

After the components have been sterilized, certain components may belubricated (action 746). As can be seen in FIG. 18, in variouscomponents, lubrication instructions 770 may be embossed or otherwiseprovided on the internal frame assembly 510. A sterile lubricationmedium such as, for example, Sodium Sterate may be applied to thevarious components as shown in FIG. 18.

The components may then be reassembled as outlined in FIG. 19. To assistwith the assembly of the components, a sterile assembly member or tray790 that has a series of complementary cavities 792, 794 therein may beemployed. See FIG. 20. One method of reassembly includes the action 750which comprises placing the rotation knob segment 28 a in thecomplementary shaped cavity 792 in the assembly tray 790. The retractknob 32 a may be placed in the complementary cavity 794 (action 752).The first housing segment 36 a may be placed in the complementary cavity796 (action 754). The translation member 138 may be placed into theright hand rotation member 28 a with the pin 166 attached theretoinserted into the stepped cam slot 148 in the cam member 136 that ismounted under the flanges 170, 172 in the right hand rotation knobsegment 28 a (action 756). The sensor cylinder 178 may be placed ontothe proximal end of the control rod 52 (action 758). The control rodassembly 125 is oriented vertically with the distal end up. The sensorcylinder 178 is retained on the control rod 52 (action 760). Theproximal end of the control rod 52 is inserted into the cavity 47 in theactuation shaft 46 (action 762). The control rod assembly 125 is thenrotated downward to the left to complete the attachment to the actuationshaft 46 (action 764). The sensor cylinder 178 is rotated until tab 544is downward (action 766). The joined firing assembly 500 and control rodassembly 125 is inserted into the first handle housing segment 36 a andthe right hand rotation knob segment 28 a in the corresponding cavities798, 792, 796 in the assembly tray 790. The lockout tab 544 on thesensor cylinder 178 is inserted into the notch 542 in the translationmember 138 (action 768). The coupling rod 60 may be aligned forinsertion into a hole (not shown) in the right hand retract knob 32 a(action 770). The second handle housing segment 36 b is then placed overthe assembly and aligned to enable the quick release fasteners 400 tocouple the handle housing segments 36 a, 36 b together (action 772). Therotation knob segment 28 b may be oriented to mate with the rotationknob segment 28 a and coupled thereto with screws 29 (action 774). Theleft hand retract knob 32 b may then be pressed onto the retractionshaft 60 to complete the assembly (action 776).

The firing lockout assembly 80 described above, as well as the firinglockout assembly disclosed in the aforementioned U.S. Pat. No.5,865,361, can be difficult to use because the clinician must depressthe plunger 82 to enable actuation shaft 46 to be actuated by cyclingthe movable handle 24. Such arrangement generally requires the clinicianto use both hands (one to hold onto the handle assembly and actuate themovable handle and the other hand to depress the plunger 82). It wouldbe more desirable to have a surgical stapling apparatus that has a moreergonomically efficient firing lockout trigger arrangement that does notrequire the clinician to use both hands to fire the instrument. FIGS.21-33 illustrate a stapling apparatus 810 that is substantially similarto the stapling apparatus 10 described above or maybe substantiallysimilar to the stapling apparatus described in U.S. Pat. No. 5,865,361or other prior surgical instruments that employ the plunger-type lockoutassembly, except that stapling apparatus 810 employs a firing lockoutsystem 880 that is much easier to use and does not require both hands tofire the instrument.

Referring to FIGS. 21 and 22, handle assembly 12 includes a handlehousing 36, which is preferably formed from molded handle housingsegments 36 a and 36 b, which collectively form stationary handle member22 and barrel portion 26 of handle assembly 12. A movable handle 824 maybe pivotably supported between handle housing segments 36 a and 36 babout pivot pin 38. See FIG. 22. A biasing member 40, that may comprisea torsion spring, biases movable handle 824 away from stationary handle22. An actuation shaft 46 may be supported within barrel portion 26 ofhandle housing 36 and includes a rack 48 of teeth 49. A driving pawl 42that has a rack engagement tooth 43 thereon may be pivotably mounted toone end of movable handle 824 about a pivot pin 44. A biasing member 50,which may comprise a torsion spring, may be employed to urge drivingpawl 42 towards rack 48 on actuation shaft 46. As movable handle 824 isactuated (e.g., pivoted), it moves driving pawl 42 such that rackengagement tooth 43 drivingly engages toothed rack 48 of actuation shaft46 to advance the actuation shaft 46 linearly in the distal direction“DD”. The forward end of actuation shaft 46 has a cavity 47 formedtherein to receive the proximal end 53 of a control rod 52 (FIG. 23)such that linear advancement of actuation shaft 46 causes correspondinglinear advancement of control rod 52.

The stapling apparatus 810 may further have a locking pawl 54 that has arack locking member 55 that may be pivotably mounted within the handlehousing 36 about pivot pin 57 and is biased towards toothed rack 48 bybiasing member 56, which is also preferably a torsion spring. Racklocking protrusion 55 of locking pawl 54 is oriented for movement into acavity 512 in actuation shaft 46, such that when rack locking protrusion55 is in the cavity 512, actuation shaft 46 is retained in alongitudinally fixed position when no disposable loading unit has beencoupled to the stapling apparatus 810.

Various embodiments may also include a retraction mechanism 58 that maycomprise a right retractor knob 32 a and a left retractor knob 32 b thatare connected to the proximal end of actuation shaft 46 by a couplingrod 60. See FIG. 22. Coupling rod 60 may include right and leftengagement portions 62 a and 62 b for receiving retractor knobs 32 a, 32b and a central portion 62 c which is dimensioned and configured totranslate within a pair of longitudinal slots 34 a respectively formedin actuation shaft 46 adjacent the proximal end thereof. A release plate64 may be operatively associated with actuation shaft 46 and is mountedfor movement with respect thereto in response to manipulation ofretractor knobs 32 a, 32 b. A pair of spaced apart pins 66 may extendoutwardly from a lateral face of actuation shaft 46 to engage a pair ofcorresponding angled cam slots 68 formed in release plate 64. Uponmovement of retractor knobs 32 a, 32 b in the proximal direction “PD”,pins 66 can release plate 64 downwardly with respect to actuation shaft46 and with respect to toothed rack 48 such that the bottom portion ofrelease plate 64 extends below toothed rack 48 to disengage engagementtooth 43 of driving pawl 42 from toothed rack 48. A slot 70 may beformed at the proximal end of release plate 64 to accommodate thecentral portion 62 c of coupling rod 60, and elongated slots 34 areprovided in the barrel section 26 of handle assembly 12 to accommodatethe longitudinal translation of coupling rod 60 as retraction knobs 32a, 32 b are pulled in the proximal direction “PD” to retract actuationshaft 46 and thus retract control rod 52 rearwardly.

The stapling apparatus 810 may further include a sensor link 882 thatmay be slidably attached to the handle housing segment 36 a by a pin orscrew 530 that extends through a slot 532 in the sensor link 882 suchthat the sensor link 882 may slide longitudinally relative to the handlehousing 36. A distal end of a spring 531 may be attached to the screw530 and the proximal end of the spring 531 may be hooked over a hook 533on the sensor link 882. See FIG. 22. Spring 531 serves to bias thesensor link 882 in the distal direction “DD”. The sensor link 882further includes a proximal locking arm 535 that has an inwardlyprotruding proximal end 537 configured to interact with the locking pawl54. In particular, when no disposable loading unit 16, 16′ is attachedto the instrument 810, the sensor link 882 is biased distally by spring531. When in that “unloaded” position, the proximal end 537 of theproximal locking arm 535 disengages the locking pawl 54 to retain thelocking pawl 54 in the locked position wherein the locking protrusion 55is received in cavity 512 to retain actuation shaft 46 in alongitudinally fixed position. Thus, when no disposable reload unit 16,16′ is coupled to the instrument 810, the instrument 810 cannot befired.

Referring to FIG. 23, a disposable loading unit sensing mechanism mayextend within stapling apparatus 810 from elongated body 14 into handleassembly 12. The sensing mechanism may include a sensor tube 176 whichis slidably supported within the outer casing 124. The distal end ofsensor tube 176 is positioned towards the distal end of elongated body14 and the proximal end of sensor tube 176 is secured within the distalend of a sensor cylinder 178′ via a pair of nubs 180′. The distal end ofa sensor link 882 is oriented in abutting relationship with the flangedproximal end 190′ of sensor cylinder 178′.

The sensor link 882 may further have a downwardly extending distal tab534 formed thereon for contact with a flange 179 formed on a sensorcylinder 178′. See FIGS. 22 and 23. As will be discussed in furtherdetail below, a sensor tube 176 is oriented to interface with the sensorcylinder 178′. See FIG. 23. When a disposable loading unit 16, 16′ iscoupled to the distal end of elongated body 14, the disposable loadingunit 16, 16′ engages the distal end of the sensor tube 176 to drivesensor tube 176 proximally, and thereby drive sensor cylinder 178′ andsensor link 882 proximally. As the sensor link 882 is moved proximally,the proximal end 537 of the proximal locking arm 535 to pivot thelocking pawl 54 such that the locking protrusion 55 moves out of cavity512 to permit actuation shaft 46 to be actuated.

The stapling apparatus 810 may also employ an articulation mechanism 120of the type and construction described in detail above, with thefollowing noted differences. In various embodiments, an articulationmechanism 120 may be supported on rotatable knob 28 and include anarticulation lever 30, a cam member 136 and a translation member 138′.In various embodiments, translation member 138′ may include a pluralityof ridges 156 which are configured to be slidably received withingrooves (not shown) formed along the inner walls of rotation knob 28.Engagement between ridges 156 and those grooves prevent relativerotation of rotation knob 28 and translation member 138′ whilepermitting relative linear movement. The distal end of translationmember 138′ may include an arm 160 which includes an opening 162configured to receive a finger 164 extending from the proximal end ofarticulation link 123. See FIG. 23.

In an assembled condition, proximal and distal stepped portions 150 and152 of cam member 136 are positioned beneath flanges 170 and 172 formedon rotation knob 28 to restrict cam member 136 to transverse movementwith respect to the longitudinal axis “L-L” of stapling apparatus 810.When articulation lever 30 is pivoted about pivot pin 140, cam member136 is moved transversely on rotation knob 28 to move stepped cammingsurface 148 (refer to FIG. 11) transversely relative to pin 166, forcingpin 166 to move proximally or distally along stepped cam slot 148. Sincepin 166 is fixedly attached to translation member 138′, translationmember 138′ is moved proximally or distally to effect correspondingproximal or distal movement of first actuation link 123. See FIGS. 23and 24.

Referring again to FIG. 24, cam member 136 may include a recess 154. Alocking ring 184 having a nub portion 186 configured to be receivedwithin recess 154 is positioned about sensor cylinder 178′ between acontrol tab portion 188′ and a proximal flange portion 190′. See FIG.23. A spring 192′ positioned between flange portion 190′ and lockingring 184 urges locking ring 184 distally about sensor cylinder 178′.When an articulating disposable loading unit 16 having an extended tipportion is inserted into the distal end of elongated body 14 of staplingapparatus 810, insertion tip causes control tab portion 188′ to moveproximally into engagement with locking ring 184 to urge locking ring184 and nub portion 186 proximally of recess 154 in cam member 136. Withnub portion 186 positioned proximally of recess 154, cam member 136 isfree to move transversely to effect articulation of stapling apparatus810. Other non-articulating disposable loading units may not have anextended insertion tip. As such, when a non-articulating disposableloading unit 16 is coupled to elongated body 14, sensor cylinder 178′ isnot retracted proximally a sufficient distance to move nub portion 186from recess 154. Thus, cam member 136 is prevented from movingtransversely by nub portion 186 of locking ring 184 which is positionedin recess 154 and articulation lever 30 is locked in its centralposition.

Referring to FIG. 23, the distal end of elongated body 14 may include acontrol rod locking mechanism 900 which may be activated during couplingof a disposable loading unit 16, 16′ with the distal end of elongatedbody 14. Control rod locking mechanism 900 may include a blocking plate902 which is biased distally by a spring 904 and includes a proximalfinger 906 having angled cam surface 908. In various embodiments, afiring shaft lock 910 that has a lock tab 912 protruding therefrom maybe employed. The lock tab 912 may be configured to selectively engage anotch 914 in the control rod 52. The firing shaft lock 910 may beprovided with a biasing member in the form of a leaf spring (not shown)or the like and have a lock pin 916 extending therethrough. The leafspring serves to bias the firing shaft lock 910 outwardly when theproximal end of the blocking plate 902 is forward in a distal position.Blocking plate 902 may be movable from a distal position spaced fromlock tab 912 to a proximal position located behind lock tab 912. In theproximal position, the blocking plate 902 causes the lock tab 912 toextend through a slot 918 in the sensor tube 176 into engagement withnotch 914 in the control rod 52.

During insertion of a disposable loading unit 16, 16′ into the distalend of elongated body 14, as will be described in further detail below,cam surface 908 of blocking plate 902 is engaged by a nub on thedisposable loading unit 16, 16′ as the disposable loading unit 16, 16′is rotated into engagement with elongated body 14 to urge plate 902 tothe proximal position. Locking tab 912, which is positioned within notch914, is retained therein by blocking plate 902 while the nub engages camsurface 908 to prevent longitudinal movement of control rod 52 duringassembly. When the disposable loading unit 16, 16′ is properlypositioned with respect to the elongated body 14, the nub on theproximal end of the disposable loading unit 16, 16′ passes off camsurface 908 allowing spring 904 to return blocking plate 902 to itsdistal position to permit subsequent longitudinal movement of controlrod 52. It is noted that when the disposable loading unit nub passes offcam surface 908, an audible clicking sound may be produced indicatingthat the disposable loading unit 16, 16′ is properly fastened to theelongated body 14.

Referring now to FIGS. 22, 25 and 26, the stapling apparatus 810 mayemploy an improved firing lockout assembly 880. In this embodiment, themovable handle 824 may be provided with a cavity 930 sized to receive aproximal portion of a firing release trigger 932. As can be seen inthose Figures, the firing release trigger 932 may have a nub 934 formedthereon and a release spring 936 may extend between the bottom of thecavity 930 and the nub 934 to apply a biasing force to the firingrelease trigger 932 in the “A” direction. As can be most particularlyseen in FIG. 26, the firing release trigger 932 may have a proximal tailportion 940 that is sized to slidably extend into a slot 825 formed inthe movable handle 824 as the firing release trigger is depressed in the“B” direction. The improved firing lock out assembly 880 may furtherinclude a gear linkage assembly 950. In various embodiments, the gearlinkage assembly 950 may include a first gear 952 that is rotatablyreceived on a first gear pin 954 that is attached to the movable handle824. First gear 952 may have a first gear segment 956 that is arrangedfor meshing engagement with a release trigger gear rack 960 formed onthe tail portion 940 of the firing release trigger 932. First gear 952may be linked to a release pawl 970 by a first connector link 972 thatis pivotally pinned or otherwise attached to the first gear 952 and therelease pawl 970. As can be seen in FIGS. 22 and 25, the release pawl970 may be pivotally supported on pin 38.

In various embodiments, release pawl 970 may have an engagement portion974 that is configured to engage a release pin 980 that is attached to asecond connector link 982 and is constrained to ride in an arcuate slot826 formed in the movable handle 824. As the present DetailedDescription proceeds, it will become apparent that the slot 826 preventsactuation of the movable handle 824 from moving the second connectorlink 982. The second connector link 982 may also be pivotally pinned orattached to a gate gear 990 that is rotatably journaled on a gear pin992 that is supported by handle housing segments 36 a, 36 b. Gate gear990 has a segment of gear teeth 994 thereon oriented for meshingengagement with a gate rack 998 formed on a locking gate 996. Thelocking gate 996 may have a slot 997 therein that is adapted to receivea portion 1002 of a gate spring 1000 that is supported on a gate pin1004 that extends between the handle housing segments 36 a, 36 b. Gatespring 1000 serves to bias the locking gate 996 in the “C” direction.See FIG. 26.

Operation of the firing lockout assembly 880 will now be described withreference to FIGS. 27-30. FIG. 27 illustrates the stapling apparatus 810prior to clamping tissue in the disposable loading unit (not shown). Ascan be seen in that Figure, the engagement portion 974 of the releasepawl 970 is not in contact with the release pin 980 at this stage ofoperation. As can also be seen, the upper end of the locking gate 996 isat the distal end of the actuation shaft 46. FIG. 28 illustrates a firstactuation of movable handle 824 to cause the staple forming anvil of thedisposable loading unit to close in the manner described above. Theclinician has not yet depressed the firing release trigger 932 and hasconveniently placed his or her index finger behind the actuation portion933 of the firing release trigger 932. By actuating the movable handle824, the actuation shaft 46 is driven in the distal direction “DD” bythe driving pawl 42 in the manner described above. As can be seen inFIG. 28, the actuation shaft 46 has moved to a position wherein the endof the locking gate 996 has entered into the locking detent 53 in theactuation shaft 46 and corresponding locking detent 53′ in the releaseplate 64. As more easily seen in FIG. 25, the upper end of the lockinggate 996 has a chamfered or tapered portion 999 formed thereon thatmeets with the vertical extending proximal side 1005 of the locking gate996. As can also be seen in FIG. 25, the locking detent 53 in theactuation shaft 46 has angled surfaces 1006, 1007 and also a verticalledge portion 1008. When the upper end of the locking gate 996 iscompletely biased into the locking detent 53 by the gate spring 1000,the proximal side 1005 of the locking gate 996 is in confrontingrelationship with the vertical ledge 1008 in the actuation shaft 46 tothereby prevent movement of the actuation shaft 46. However, when thelocking gate 996 is pulled in the direction “D”, the angled surfaces1006, 1007, as well as the chamfered surface 999 on the locking gate996, enable the actuation shaft 46 to move longitudinally past thelocking gate 996 without the locking gate 996 having to be completelybiased out of contact with the actuation shaft 46.

Returning to FIG. 28, when in that position, the slot 826 in the movablehandle 824 permitted the movable handle to be pulled toward thestationary handle portion 22 without causing the pin 980 to move thesecond connection link 982 which in turn would actuate the locking gate996. As can be seen in FIG. 28, the spring 1000 has biased the lockinggate 996 into the blocking position wherein the locking gate 996 isreceived in locking detents 53, 53′ and the proximal surface 998 thereofis in confronting relationship with the vertical ledge 1008 in theactuation shaft 46. After the movable handle 824 has been pulled to thefirst position shown in FIG. 28 to close the staple forming anvil, theclinician then permits the movable handle 824 to move to the positionillustrated in FIG. 29 under the biasing force of the handle closurespring 40. At this stage, the retractor knobs 32 a, 32 b could be pulledproximally to cause the staple forming anvil to unclamp the tissue inthe event that the clinician wishes to re-manipulate the tool 17 or, theclinician may wish to commence the firing cycle by placing his or herindex finger on the actuation portion 933 of the firing release trigger932 as illustrated in FIG. 30.

In FIG. 31, the clinician has depressed the firing release trigger 932.Such action causes the release trigger gear rack 960 in the releasetrigger tail portion 940 to mesh with the first gear segment 956 on thefirst gear 952 to cause the first gear 952 to rotate in thecounterclockwise direction “CCW”. As the first gear 952 rotates in thecounterclockwise direction, it pushes the first connector link 972 inthe “E” direction, causes the release pawl 970 to rotate in theclockwise “C” direction. As the release pawl 970 rotates in the “C”direction, the engagement surface 974 contacts release pin 980 and drawsthe second connection link 982 in the “F’ direction. As the secondconnector link 982 moves in the “F” direction, it causes the gate gear990 to rotate in the counterclockwise direction “CCW”. The gear teeth994 on the gate gear 990 mesh with the gate rack 998 and drive thelocking gate 996 in the “D” direction out of blocking engagement withthe locking detents 53, 53′.

FIG. 32 illustrates the position of the locking gate 996 relative to theactuation shaft 46 as the actuation shaft 46 begins to move in thedistal direction “DD” by actuating the movable handle 824. As can beseen in that Figure, the upper chamfered portion 999 of the locking gate996 is now in contact with the vertical edge 1005 in the actuation shaft46 and permits the actuation shaft 46 to move distally. FIG. 33illustrates the completion of a first firing stroke of the movablehandle 824. As can be seen in that Figure, the upper end of the lockinggate 996 rides on the bottom of the actuation shaft 46 and the plate 64as the actuation shaft 46 is advanced in the distal direction “DD”. Link982, proximal end has moved to the proximal end of slot 826 during thatstroke.

FIG. 34 illustrates an alternative stapling apparatus embodiment 810′that employs an alternative firing lockout assembly 880′ that may besubstantially the same as the firing lockout assembly 880 describedabove, except for the differences noted below. In particular, the firinglock out assembly 880′ employs a flexible bar 1020 that is constrainedto move in a serpentine passage 828 formed in the movable handle 824′.The flexible bar 1020 replaces the first gear 952, the first connectorlink 972, and the release pawl 970. One end of the flexible bar 1020 iscoupled to the firing release trigger 932 and the other end of theflexible bar 1020 is constrained to contact the release pin 980 which isalso constrained to move in the slot 828. Thus, as the firing releasetrigger 932 is depressed, the flexible bar 1020 pushes the release pin980 which causes the second connector link 982 to move in the “F”direction. As the second connector link 982 moves in the “F” direction,the gate gear 990 moves in the counter clockwise direction “CC” anddrives the locking gate 996 in the “D” direction. When the clinicianreleases the firing release trigger 932, the release spring 936 drivesthe firing release trigger 932 in the “A” direction pulling the flexiblebar 1020 away from the release pin 980, thereby permitting the releasepin 980 to move unconstrained in the slot 828. As the release pin 980 isunconstrained, the gate spring 1000 is permitted to bias the lockinggate 996 in the “C” direction. As the locking gate 996 is biased in the“C” direction, the gate gear 990 is driven unconstrained in a clockwise“C” direction. Those of ordinary skill in the art will appreciate thatthe firing lockout arrangements 880, 880′ described above enable theclinician to operate the instruments with one hand. This represents avast improvement over those firing lockout systems disclosed in U.S.Pat. No. 5,865,361 and other prior stapling apparatuses configured foruse with disposable loading units.

FIGS. 35-46 depict a surgical stapling apparatus 1210 that addresses atleast some of the aforementioned problems associated with prior surgicalstapling apparatuses that are designed to accommodate articulatabledisposable loading units. More particularly and with reference to FIG.35, the surgical stapling apparatus 1210 may be substantially similar inconstruction as the various instruments described above, except for theselectively lockable rotation system 1220 and the articulation system1320 (FIG. 36) as will be described in detail below. Those componentsthat are the same as the components employed in the above-mentionedembodiments will be labeled with the same element numbers and those ofordinary skill in the art can refer to the disclosure set forthhereinabove that explains their construction and operation.

In one embodiment, the surgical stapling apparatus 1210 may include ahandle assembly 12 that has an elongated body 14 that is operablycoupled thereto and which protrudes distally therefrom. A distal end ofthe elongated body 14 may be coupled to an articulatable disposableloading unit 16. The disposable loading unit 16 may include a toolassembly 17 that is selectively articulatable about an articulation axis“A1-“A1” by articulation motions transferred thereto by the elongatedbody 14 as is known. See FIG. 35. In various embodiments of the presentinvention, the proximal end of the elongated body 14 may be coupled to arotatable shroud 1260 that is coupled to handle housing 36′. As can beseen in FIGS. 36, 44 and 45, handle housing 36′ may include an annularchannel 117 configured to receive an annular rib 1262 formed on theproximal end of rotatable shroud 1260, which is preferably formed frommolded shroud segments 1260 a and 1260 b. Annular channel 117 and rib1262 permit relative rotation between shroud 1260 and handle housing36′. Rotation of rotatable shroud 1260 causes the elongated body 14 andthe disposable loading unit attached thereto to rotate about thelongitudinal axis “L-L” defined by the elongated body 14. Variousembodiments of surgical stapling apparatus 1210 may include aselectively lockable rotation system 1220 for selectively locking therotatable shroud 1260 to prevent rotation thereof (as well as rotationof elongated body 14 and disposable loading unit 16) relative to thehandle assembly 12 about the longitudinal axis “L-L”.

In various embodiments, the lockable rotation system 1220 may include acylindrical distal cover 1222 formed or otherwise provided on the distalend of the handle housing 36′. FIG. 36 illustrates housing segment 36 a′of handle housing 36′ that has one cover segment 1222 a formed thereon.Those of ordinary skill in the art will understand that the housingsegment 36 b′ of handle housing 36′ has a mating cover segment 1222 bformed thereon that cooperates with cover segment 1222 a to form distalcover 1222. See FIG. 40.

The lockable rotation system 1220 may further include a brake system1229. In particular, cover segment 1222 a may have an internal splinesection 1224 a and cover segment 1222 b may have an internal spline 1224b. Internal spline sections 1224 a, 1224 b cooperate to form an internalspline 1224 which is configured to support a brake tube 1230 of thebrake system 1229. In various embodiments, the brake tube 1230 has anexternal spline 1232 formed thereon that is sized to be received ininternal spline 1224 in the distal cover 1222 such that the brake tube1230 can move axially relative to the distal cover 1222, but isconstrained to rotate therewith. The brake system 1229 may furtherinclude a brake band 1240 that interacts with a brake arm pin 1250 thatis operably supported in a rotatable shroud 1260. The operation of thebrake arm pin 1250 and brake band 1240 will be discussed in furtherdetail below.

The brake tube 1230 may be moved axially relative to the cylindricaldistal cover 1222 by a switch bar 1270 that is operably connected to aselector switch assembly 1290. As can be seen in FIG. 36, the switch bar1270 has a proximal end 1272 and a distal end 1276. The proximal end1272 may have a hole 1274 for receipt of a shaft portion 1294 of aselector switch 1292. The shaft portion 1294 extends through the hole1274 in the switch bar 1270 and is pinned thereto by a cross pin 1296.In addition, the selector switch 1292 may have a fastener pin 1298 thatpivotally couples the shaft portion 1294 to the housing 36′. A detentspring 1300 may be employed to lock the selector switch 1292 inposition. The detent spring 1300 may have a bulbous portion 1302 that isadapted to be engaged by the cross pin 1296 as the selector switch 1292is pivoted distally and proximally about a axis “SA-SA” defined byfastener pin 1298. See FIG. 36. Thus, as the selector switch 1292 ispivoted to the proximal position (FIGS. 42, 43 and 46) and as theselector switch 1292 is pivoted to the distal position (FIGS. 37, 38, 41and 45) the bulbous portion 1302 of spring 1300 retains the selectorswitch 1292 and the switch bar 1270 in position.

Referring again to FIG. 36, the distal end 1276 of the switch bar 1270may have a connector pin 1278 protruding therefrom that is adapted tocouple the switch bar 1270 to the brake tube 1230. See FIG. 38. Thus,linear movement of the switch bar in the proximal direction “PD” anddistal direction “DD” causes the brake tube 1230 to also move in thosedirections within the cylindrical distal cover portion 1222. As can alsobe seen in FIGS. 36-39 and 41-46, the distal end 1276 of the switch bar1270 may further have a bolt 1280 formed thereon or attached thereto.The bolt 1280 is adapted to selectively meshingly engage a rotation lockring 1264 that comprises a series of teeth 1266 formed on or otherwiseprovided on the annular rib 1262. As can be seen in FIG. 36, the annularchannel 117 in the cylindrical distal cover 1222 is formed by a inwardlyextending flange 1226 that has a groove 1228 therethrough to receive thedistal end 1276 of the switch bar 1270 therethrough. Thus, as will bediscussed in further detail below, when the switch bar 1270 is moved inthe distal direction “DD”, the bolt 1280 can be brought into meshingengagement with the teeth 1266 of the rotation lock ring 1264 of theshroud 1260 and thereby prevent the shroud 1260 from rotating withrespect to the cover 1222 and shroud 36. See FIG. 44.

Various embodiments of the surgical stapling apparatus 1210 may furtherinclude a unique and novel articulation system 1320 which, as will bedescribed below, interfaces with the components forming the elongatedbody 14 to selectively apply articulation motions thereto for transferto the disposable loading unit 16. The articulation system 1320 mayinclude a translation member 138′. For example, the translation member138′ may include a plurality of ridges 156 which are configured to beslidably received within grooves 1261 formed along the inner walls ofthe shroud 1260. Engagement between ridges 156 and those grooves 1261(FIGS. 36 and 37) prevents relative rotation of the translation member138′ and the shroud 1260 while permitting relative linear movementbetween those components. The distal end of translation member 138′ mayinclude an arm 160 which includes an opening 162 configured to receive afinger 164 extending from the proximal end of articulation link 123. SeeFIG. 37. Also in this embodiment, the translation member 138′ has anarticulation pin 166 protruding therefrom that extends through anarticulation slot 1265 in the articulation shroud 1260. The articulationpin 166 is received in a hole 1324 (FIG. 36) formed in a lineararticulation and rotation grip 1320 that is received on the shroud 1260.The articulation system may further include a linear articulation androtation grip 1322 that may be fabricated from two grip segments 1322 a,1322 b that are coupled together about the shroud 1260. The hole 1324may be provided in the grip segment 1322 a as shown in FIG. 36. Thus,when the clinician moves the grip 1322 axially in the proximal direction“PD” and distal direction “DD”, the translation member 138′, as well asthe articulation link 123, moves in those directions to effectuatearticulation of the articulatable disposable loading unit.

Also in this embodiment, the brake system 1229 may be configured toprevent actuation of the articulation system 1320. For example,referring again to FIG. 36, the band brake 1240 may be configured to bereceived within spaced shoulder flanges 1267 formed on the exterior ofshroud 1260 to form a brake band groove 1269. As can be seen in FIG. 36,the brake band 1240 does not form a complete ring; the ends 1242 of theband brake 1240 are in spaced confronting relationship relative to eachother to define a cam-receiving opening 1244 therebetween. The brakeband 1240 is installed within the brake band groove 1269 such that thecam opening 1242 is oriented to receive a brake cam 1330 therein.Attached to the brake cam 1330 is a brake arm shift pin 1332 thatextends through a brake cam hole 1334 in the shroud 1260. As can be seenin FIG. 37 the brake arm shift pin 1332 is configured to be receivedwithin a shifting groove 1234 formed in the distal end of the brake tube1230. The linear articulation and rotation grip 1322 which comprises aportion of the articulation system 1320 has an undercut area 1326therein to enable the grip 1320 to move axially relative to the shroud1260. In various embodiments, the grip segment 1322 a may be providedwith a series of detents 1328 that is adapted to engage an indicator pin1263 (FIG. 41) protruding from the shroud 1260 such that as the grip1320 is axially moved on the shroud 1260, the indicator pin 1263 makesan audible click or sound as it engages the detents 1328. Five detents1328 are illustrated in that Figure; other numbers of detents 1328 maybe used.

The operation of the surgical stapling apparatus 1210 will now bedescribed with reference to FIGS. 37-39, 41, and 42-44. FIGS. 37-39illustrate the stapling apparatus 1210 in the “rotation” mode whereinthe outer casing 124 may be selectively rotated about longitudinal axis“L-L”. As can be seen in FIGS. 37 and 38, the selector switch 1292 ispivoted to the distal position wherein the switch bar 1270 is pulled inthe proximal direction “PD”. When the switch bar 1270 is pulled in theproximal direction, the rotation bolt 1280 is disengaged from therotation lock ring 1264 (FIG. 39) thereby permitting the shroud 1260 torotate about longitudinal axis “L-L”. As discussed above, the proximalend of casing 124 includes diametrically opposed openings 128, which aredimensioned to receive radial projections 132 formed inside the distalend of shroud 1260. See FIGS. 36 and 38. Projections 132 and openings128 fixedly secure shroud 1260 and elongated body 14 in relation to eachother, both longitudinally and rotatably. Rotation of shroud 1260 withrespect to handle assembly 12 thus results in corresponding rotation ofelongated body 14 about longitudinal axis L-L with respect to handleassembly 12. Also, because the switch bar 1270 is coupled to the braketube 1230 by connector pin 1278, as the switch bar 1270 is moved in theproximal direction “PD”, the brake tube 1230 also moves in the proximaldirection within the cylindrical distal cover 1222. As explained above,the shift pin 1332 of the brake cam 1330 is received in a shiftinggroove 1234 in the brake tube 1230. When the brake tube 1230 is movedproximally, the shift pin 1332 that is a distal feature of a radius armthat in turn is rigidly affixed to the pin 1250 rotates brake cam 1330such that it forces the ends 1242 of the brake band 1240 radiallyoutwardly to thereby lock the linear articulation and rotation grip 1322to the shroud 1260. The brake band 1240 prevents the grip 1322 frommoving axially on the shroud 1260; however, rotation of the grip 1322causes the shroud 1260 to rotate about axis “L-L”. Thus, when theselector switch 1292 is pivoted to the distal direction, the elongatedbody 14 and disposable loading unit attached thereto may be rotatedabout the longitudinal axis “L-L” by rotating the grip 1320.

When the clinician desires to articulate the disposable loading unit,the selector switch 1292 is pivoted in the proximal direction “PD”illustrated in FIGS. 42, 43 and 46. As can be seen FIGS. 42, 43 and 46,when the selector switch 1292 is pivoted to the proximal direction, theswitch bar 1270 is axially advanced in the distal direction “D-D”bringing the rotation bolt 1280 into locking engagement with therotation lock ring 1264. When the locking bolt 1280 is engaged with therotation locking ring 1264, the shroud 1260 (and the elongated body 14and casing 124) are unable to rotate relative to the handle assembly 12about the longitudinal axis “L-L”. When the switch bar 1270 is moved inthe distal direction, the brake tube 1230 is also moved in the distaldirection “D-D” because the switch bar 1270 is attached thereto. As thebrake tube 1230 moves proximally, the shift pin 1332 is caused to rotateand rotates brake cam 1330 such that it permits the ends 1242 of thebrake band 1240 to move inwardly toward each other to thereby permit thegrip 1320 to be moved relative to the shroud 1260. See FIG. 46. Invarious embodiments, an articulation pin 166 extends from translationmember 138′ through a slot 1265 in the shroud segment 1260 a and isreceived in a hole 1324 in the grip segment 1322 a. See FIGS. 36 and 37.Thus, when the clinician moves the rotation grip 1322 axially in theproximal direction “PD” and distal direction “DD”, the translationmember 138′ as well as the articulation link 123 which is attachedthereto by an arm 160 also moves. Thus, when the clinician moves therotation grip 1322 axially in the proximal direction “PD” and distaldirection “DD”, the translation member 138′ as well as the articulationlink 123 also moves in those directions to effectuate articulation ofthe articulatable disposable loading unit. In addition, as the grip 1322is axially moved on the shroud 1260, the indicator pin 1263 makes anaudible click or sound as it engages the detents 1328 to provide theclinician with an audible indication of the progress of the articulationmotion.

FIG. 46 depicts use of translation member 138 that has an upstanding armportion 540 and an arm 546 which includes an opening 548 configured toreceive a finger (not shown) extending from the proximal end ofarticulation link 123 (not shown). See FIGS. 4 and 11. Pin 166 issecured to translation member 138 and dimensioned to extend through theslot 1265 in the shroud and into the hole 1324 in the shroud 1322. Thisembodiment otherwise works the same as the embodiments depicted in FIGS.37 and 38. Those of ordinary skill in the art will recognize that theaforementioned embodiment represents a vast improvement over priorinstruments adapted for use with disposable loading units such as thosedisclosed in U.S. Pat. No. 5,865,361. In particular, in the embodimentsdescribed above, the clinician may rotate the disposable loading unit tothe desired position and then lock the shroud 1260 to prevent furtherrotation of the shroud 1260. The clinician may then articulate thedisposable loading unit while the shroud 1260 remains locked inposition. In prior units, the rotation knob was free to rotate while theclinician was trying to articulate the disposable loading unit. Thus, toprevent the disposable loading unit from rotating, the clinician had tomanipulate the articulation lever while being careful not to impart arotation motion to the rotation knob. The above-described embodimentssolve that problem.

FIGS. 47-51 illustrate another surgical stapling apparatus 1410 of thepresent invention constructed for use with a disposable loading unit(not shown) that permits a clinician to articulate and fire thedisposable loading unit with one hand. More particularly and withreference to FIG. 47, the surgical instrument 1410 is substantiallysimilar in construction as the various instruments described above,except for the articulation system 1420 as will be described in detailbelow. Those components that are the same as the components employed inthe above-mentioned embodiments will be labeled with the same numbersand those of ordinary skill in the art can refer to the disclosure setforth hereinabove that explains their construction and operation.

In one embodiment, the surgical stapling apparatus 1410 may include ahandle assembly 12 that has an elongated body 14 that is operablycoupled to the handle assembly 12 and protrudes distally therefrom. Adistal end of the elongated body 14 may be coupled to an articulatabledisposable loading unit 16. The disposable loading unit may include atool assembly 17 that is selectively articulatable about an articulationaxis “AA-“AA” by articulation motions transferred thereto by theelongated body 14 as is known.

The handle assembly 12 may comprise a handle housing 36 and have amovable handle 24 operably coupled thereto that is movable throughactuation strokes relative to the handle housing 36. As in theabove-described embodiments, actuation of the movable handle 24 maycause longitudinal actuation motions to be applied to an actuation shaft46 which is operably coupled to a control rod 52 which comprises aportion of the elongated body 14. As can be seen in FIGS. 48-51, thearticulation system 1420 may include an articulation trigger 1422 thatmay be shaped and oriented relative to the stationary portion 22 of thehandle housing 36 and the movable handle 24 to enable the clinician toactuate it with his or her index finger of the hand that is grasping thehandle assembly 12 and which actuates the movable handle 24. The trigger1422 may have a drive bar portion 1424 attached thereto that has avertical portion 1426 that is pivotally pinned to the handle housing 36by a pivot pin 1428 such that the articulation trigger 1422 may beselectively pivoted in the “G” and “H” directions about pivot pin 1428.See FIG. 49. The drive bar portion 1424 may further have a drive portion1430 that has a slot 1432 therein adapted to receive a drive pin 1434attached to an articulation bar 1440. As can be seen in FIG. 49, thearticulation bar 1440 may be provided with a pair of elongated slots1442, 1444 that are adapted to receive portions of screws 1450, 1452,respectively. Screws 1450, 1452 extend through the elongated slots 1442,1444, respectively and are attached to the handle housing segment 36 asuch that the articulation bar 1440 is constrained to movelongitudinally within handle housing 36 in the proximal direction “PD”and the distal direction “DD”. The distal end of the articulation bar1440 may have an articulation pin 1446 that is adapted to extend into anannular groove 139″ provided in the proximal end of the translationmember 138″ which may be otherwise identical in construction andoperation with respect to translation member 138′ described in detailabove. That is, the translation member 138″ may have a plurality ofridges 156 which are configured to be slidably received within groovesformed along the inner walls of the rotatable knob 28″. Engagementbetween ridges 156 and those grooves prevent relative rotation of thetranslation member 138″ and the rotatable knob 28″ while permittingrelative linear movement between those components. The distal end oftranslation member 138″ may include an arm 160 which includes an opening162 configured to receive a finger 164 extending from the proximal endof articulation link 123. See FIGS. 48 and 49. Thus, when the clinicianactuates the articulation trigger 1422 in the “G” direction, the driveportion 1430 pulls the articulation bar 1440 in the proximal direction“PD” which also pulls the translation member 138″ and the articulationlink 123 attached thereto in the proximal direction “PD” which maythereby cause the disposable loading unit coupled thereto to articulatein the right hand direction in the manner described above andhereinbelow. When the clinician pulls the articulation trigger 1422 inthe “H” direction, the drive portion 1430 pushes the articulation bar1440 in the distal direction “DD” which also pushes the translationmember 138″ and the articulation link 123 attached thereto in the distaldirection “DD” which may thereby cause the disposable loading unitcoupled thereto to articulate in the left hand direction.

As indicated above, this embodiment may include a sensor cylinder 178′that interfaces with a sensor tube 176 and a sensor link 182 as wasdescribed above to detect whether a disposable reload unit has beencoupled to the control rod 52 and prevent actuation of the articulationmechanism 1420 when no disposable reload unit has been attached. In thisembodiment, however, the flange 190′ of the sensor tube 178′ isconfigured to interact with a “no reload” lockout ramp 1448 formed onthe articulation bar 1440. See FIGS. 50 and 51. When no disposableloading unit has been coupled to the elongated member 14 and control rod52, the sensor tube 178′ is biased into the position illustrated in FIG.50. As can be seen in that Figure, the no reload lockout ramp 1448 onthe articulation bar 1440 is engaged with the flange 190′ on the sensortub 178′ such that the articulation bar 1440 is biased laterally outwardin the “I” direction. As can also be seen in that Figure, an inwardlyextending locking detent 37 is formed on the handle housing segment 36 aand is adapted to be received in a locking notch 1445 in thearticulation bar 1440 when the flange 190′ engages the no reload lockoutramp 1448 to bias the articulation bar 1440 in the “I” direction. Whenthe detent 37 is received in the locking notch 1445, the articulationbar 1440 cannot be actuated. Thus, when no disposable loading unit iscoupled to the instrument 1410, the articulation trigger 1422 cannot beactuated. When a disposable loading unit is coupled to the elongatedmember 14 and control rod 52 and sensor bar 176, the sensor cylinder178′ is biased in the proximal direction “PD” which causes the flange190′ to disengage the non reload lockout ramp 1448 as shown in FIG. 51and thereby permit the articulation bar 1440 to move. Thus, thearticulation trigger 1422 may be actuated when a disposable loading unithas been coupled to the stapling apparatus 1410.

Those of ordinary skill in the art will appreciate that the articulationmechanism 1420 described above enable the clinician to operate theinstrument with one hand. This represents a vast improvement over thosearticulation mechanisms disclosed in U.S. Pat. No. 5,865,361 and otherprior stapling apparatuses configured for use with disposable loadingunits.

FIGS. 52-64 disclose another surgical stapling apparatus 1510 of thepresent invention constructed for use with an articulatable disposableloading unit (not shown) that permits a clinician to articulate and firethe disposable loading unit by manipulating the movable handle 24″. Inone embodiment, the surgical stapling apparatus 1510 may include ahandle assembly 12 that has an elongated body 14 that is operablycoupled to the handle assembly 12 and protrudes distally therefrom. Adistal end of the elongated body 14 may be coupled to an articulatabledisposable loading unit 16. The disposable loading unit may include atool assembly 17 that is selectively articulatable about an articulationaxis “A1-A1” by articulation motions transferred thereto by theelongated body 14 as is known. As will be discussed in detail below, thesurgical stapling apparatus 1510 may employ a unique and novel selectorarrangement 1512 that interfaces with the movable handle 24″, theactuation shaft 46 and an articulation system 1520. When the selectorarrangement 1512 is in a “firing” orientation, manipulation of themovable handle member 24″ through actuation strokes imparts a firingmotion to the actuation shaft 46 and when the selector arrangement 1512is in an “articulation” orientation, manipulation of the movable handle24″ through the actuation strokes actuates the articulation system 1520.Those components that are the same as the components employed in theabove-mentioned embodiments will be labeled with the same numbers andthose of ordinary skill in the art can refer to the disclosure set forthhereinabove that explains their construction and operation.

As can be seen in FIGS. 52 and 53, the selector arrangement 1512 mayinclude an articulation selector switch 1522 that is located outside ofthe handle housing 36 to provide access thereto. The articulationselector switch 1522 may be coupled to an articulation selector switchshaft 1524 that extends through the handle housing segment 36 b and isattached to a rocker mount 1530 which comprises a portion of thearticulation system 1520. A second articulation selector switch shaft1526 protrudes outward from the other side of the rocker mount 1530 toextend through the handle housing segment 36 a for attachment to aselector switch 1522 a such that the rocker mount 1530 is pivotableabout rocker axis “RA” defined by the shafts 1524, 1526. See FIG. 60. Ascan be seen in FIGS. 56-58, the articulation system 1520 furtherincludes a first articulation gear 1540 and a second articulation gear1550 that are each freely rotatable within the rocker mount 1530. Thefirst and second articulation gears 1540 and 1550 are oriented forselective engagement with an articulation bar extension 1441′ thatcomprises a portion of articulation bar 1440′, which is otherwisesimilar to articulation bar 1440 described above. As can be seen in FIG.55, the articulation bar extension 1441′ has a series of holes 1443′therein adapted to be engaged by the first and second articulation gears1540, 1550, depending upon the orientation of the rocker mount 1530.

The selector arrangement 1512 may further include a unique and novelgear selector switch assembly 1560 for interfacing between a firing gear1610 and an articulation transfer gear train 1600 that comprises aportion of the articulation system. In various embodiments, thearticulation transfer gear train 1600 may comprise a first transfer gear1602 that is mounted to a first transfer gear shaft 1604 that isrotatably supported in sockets (not shown) in the handle housingsegments 36 a, 36 b and a second transfer gear 1606 that is mounted on asecond transfer gear shaft 1608 that is rotatably supported in sockets(not shown) in the handle housing segments 36 a, 36 b. In variousembodiments, the gear selector switch assembly 1560 may include afunction selector switch 1562 that has a pair of pins 1563 protrudingtherefrom that extend through corresponding arcuate slots 1564 in thehandle housing segment 36 b and are attached to a drive disc 1566. SeeFIGS. 61 and 62. As can be seen in those Figures, the drive disc 1566may have a series of teeth-receiving cavities 1568 therein that areadapted to selectively mesh with corresponding disc teeth 1571 in ashift disc 1570. The shift disc 1570 may be non-rotatably affixed to astationary shaft 1574. As can be seen in FIGS. 61 and 62, an end 1575 ofthe stationary shaft 1574 may be received in a cavity 1577 and pinnedthereto by a lock pin 1578. In various embodiments for example, the end1575 may be molded into the handle housing segment 36 a such thatstationary shaft 1574 is not rotatable relative thereto. As can also beseen in FIG. 62, the shift disc 1570 may be non-rotatably pinned tostationary shaft 1574 by a shift pin 1580 that extends through atransverse slot 1576 in the stationary shaft 1574 to enable the shiftdisc 1570 to move axially (and non-rotatably) on the stationary shaft1574.

As can also be seen in FIGS. 61 and 62, the gear selector switchassembly 1560 may further include a drive gear assembly 1590 thatcomprises a drive gear portion 1592 and an articulation drive gearportion 1594. The drive gear assembly 1590 is configured to move axiallyon the stationary shaft 1574 and is biased in the “J” direction by aspring 1596 that is journaled on the stationary shaft 1574.

The operation of the articulation system 1520 will now be described withreference to FIGS. 57 and 58. To commence the articulation process, theclinician actuates one of the articulation selector switches 1522 a,1522 b. In one embodiment, for example, if the clinician desires toarticulate the disposable loading unit to the right, the clinicianpivots the articulation selector switches 1522 a, 1522 b downward (arrow““L” in FIG. 52). By pivoting the selector switches 1522 downward, therocker mount 1530 is pivoted in the counterclockwise direction “CCW” inFIG. 58 to bring the second articulation gear 1550 into meshingengagement with the holes 1443′ in the articulation bar extension 1441′.In the articulation mode, the gear selector switch assembly 1560 ispermitted to remain in the unactuated position illustrated in FIGS. 59and 63. When in that position, the drive gear assembly 1590 ispositioned such that a handle gear 1620 attached to or otherwise moldedto the movable handle 24 is in meshing engagement with the drive gearportion 1592 of the drive gear assembly 1590. In addition, thearticulation drive gear portion 1594 of the drive gear assembly 1590 isin meshing engagement with the first transfer gear 1602. As can be seenin FIG. 59, when the drive gear assembly 1590 is positioned in thatmanner, the firing gear 1610, which is rotatably supported on a firinggear shaft 1612, is not engaged with the drive gear assembly 1590. Thus,actuation of the movable handle 24 will not affect the firing gear 1610.

When the selector switches 1522 a, 1522 b, 1562 are positioned in themanner described immediately above, the clinician may articulate thedisposable loading unit attached to the stapling apparatus 1510 byactuating (ratcheting or pivoting) the movable handle 24. As the movablehandle 24 is actuated, the handle gear 1620 rotates in thecounterclockwise direction “CCW” which, in turn, causes the drive gear1592 to rotate in the clockwise direction “CW” which, in turn, causesthe first transfer gear 1602 to rotate in the counterclockwise direction“CCW” which, in turn, causes the second transfer gear 1606 to rotate inthe clockwise direction “CW” which, in turn, causes the firstarticulation gear 1540 to rotate in the counterclockwise direction “CCW”which, in turn, causes the second articulation gear 1550 to rotate inthe clockwise direction “CW” which, in turn, drives the articulation barextension 1441′ in the proximal direction “PD”. See FIG. 58. As thearticulation bar extension 1441′ is driven in the proximal direction“PD”, the articulation bar 1440′ drives the translation member 138″ andthe articulation link 123 attached thereto is drawn in the proximaldirection “PD” which may thereby cause the disposable loading unitcoupled thereto to articulate in the right hand direction in the mannerdescribed above and hereinbelow. To articulate the disposable loadingunit to the left, the clinician pivots the articulation selectorswitches 1522 a, 1522 b in the up direction (the “M” direction in FIG.52). When the selector switches 1522 a, 1522 b are pivoted in thatdirection, the articulation rack 1530 is pivoted in the clockwisedirection “CW” about the rack axis “RA” to thereby bring the firstarticulation gear 1540 into meshing engagement with the articulation barextension 1441′. Because the first articulation gear 1540 is rotating inthe clockwise direction “CW”, the first articulation gear 1540 drivesthe articulation bar extension 1441′ in the distal direction “DD” as themovable handle is actuated. As the articulation bar extension 1441′ isdriven in the distal direction “DD”, the articulation bar 1440′ drivesthe translation member 138″ and the articulation link 123 attachedthereto in the distal direction “DD” which may thereby cause thedisposable loading unit coupled thereto to articulate in the left handdirection. Also in this embodiment, the articulation bar 1440′ mayemploy the locking arrangement described above with respect toarticulation bar 1440 for preventing movement of articulation bar 1440′when no disposable loading unit has been coupled to the staplingapparatus 1510. Thus, in this embodiment, the articulation motions aregenerated by actuating the movable handle 24.

This embodiment may also employ a unique and novel firing systemgenerally designated as 1601, of which firing gear 1610 is a part. Moreparticularly and with reference to FIGS. 55-60, the firing assembly 1601may also include a pawl slide 1640 that is movably supported in a righthand rack guide 1630 a formed in the right hand housing segment 36 a anda left hand rack guide 1630 b formed in the left hand housing segment 36b as shown in FIG. 54 (the housing segments 36 a, 36 b have been omittedfor clarity in FIG. 54). In various embodiments, the pawl slide 1640 maygenerally have the shape of a capital “I” with a distal cross barportion 1642, central bar portion 1644 and a proximal cross bar portion1646. The cross bar portions 1642, 1646 serve to slidingly support thepawl slide 1640 in the rack guides 1630 a, 1630 b such that the pawlslide 1640 is able to axially move in the proximal direction “PD” andthe distal direction “DD”. Also in this embodiment, a drive rack 1650may be formed on the bottom of, or otherwise attached to, the bottom ofthe central bar portion 1644 of the pawl slide 1640. The firing rack1650 is oriented in meshing engagement with the firing gear 1610 as willbe discussed in further detail below. Also attached to the central barportion 1644 is a pawl 42 that has a rack engagement portion 43 fordriving engagement of the rack 48 on the actuation shaft 46. As shown inFIGS. 55 and 64, the pawl 42 in various embodiments may be stamped outof metal and formed in a substantially U-shape such that the pawl 42 maybe pivotally pinned to the central bar portion 1644 by a pivot pin 44′.A pawl spring 50′ may be supported in a hole 1645 in the central barportion 1644 to bias the pawl 42 into meshing engagement with the rack48 on the actuation shaft 46. See FIG. 64.

The operation of the firing system 1601 will now be described withreference to FIGS. 60 and 64. To commence the firing process, theclinician turns the gear selector switch assembly 1560 to the positiondepicted in FIG. 64, such that the drive gear assembly 1590 is biased inthe “K” direction such that the handle gear 1620 remains in meshingengagement with the drive gear 1592 and the articulation gear 1594 ofthe drive gear assembly 1590 does not mesh with the first articulationtransfer gear 1602. In addition, the drive gear 1592 is in meshingengagement with the firing gear 1610 which, as described above, is inmeshing engagement with the firing rack 1650. Because the articulationdrive gear 1594 does not mesh with the first articulation transfer gear1602, actuation of the movable handle 24″ will not result in thegeneration of any articulation motions.

When selector switch 1562 is positioned in the manner describedimmediately above, the clinician may fire the actuation shaft 46 which,in turn, transfers firing motions to the control rod 52 coupled to theactuation shaft 46 which, in turn, transfers firing motions to thedisposable loading unit coupled thereto in the manner described in U.S.Pat. No. 5,865,361. As illustrated in FIG. 56, the actuation shaft 46 ofthis unique and novel embodiment is fired (or moved in the distaldirection “DD”) by actuating (ratcheting or pivoting) the movable handle24. As the movable handle 24″ is actuated, the handle gear 1620 rotatesin the counterclockwise direction “CCW” which, in turn, causes the drivegear 1592 to rotate in the clockwise direction “CW” which, in turn,causes the firing gear 1610 to rotate in the counterclockwise direction“CCW” and drive the firing rack 1650 and pawl 42 attached thereto in thedistal direction “DD”. The rack engagement portion 43 of the pawl 42 isin engagement with the teeth 49 of the rack 48 on the actuation shaft 46and thereby drives the actuation shaft 46 in the distal direction “DD”.This embodiment otherwise operates as described above. In particular,the clinician continues to ratchet the movable handle 24″ until thefiring sequence has been completed. When the movable handle 24″ ispivoted to a position adjacent the stationary handle portion 22, theclinician releases the movable handle 24″ and the movable handle 24″ ispivoted to the starting position by the spring 40 (described above) andthen the movable handle 24″ can be pivoted again for another stroke toadvance the pawl 42 and the actuation shaft 46. When the movable handle24″ is released, the rack engagement tooth 43 of the pawl 42 slides overthe teeth 49 on the actuation shaft rack 48 as the pawl moves in theproximal direction “PD” and then reengages the teeth 49 when the movablehandle 12 is pivoted to drive the actuation shaft in the distaldirection “DD”.

Those of ordinary skill in the art will understand that the staplingapparatus 1510 is equipped with a movable handle 12 that can be used tofire the instrument as well as to articulate the disposable loading unitattached thereto. It will be further appreciated that such embodimentsare able to generate higher articulation forces than another priordevices such as those disclosed in U.S. Pat. No. 5,865,361.

FIGS. 65-69 illustrate an alternative articulation mechanism 1720 foraxially advancing the translation member 138 to ultimately result in thelongitudinal actuation of an articulation link (not shown in FIG. 65).As can be seen in FIGS. 65 and 66, the articulation mechanism 1720 maybe used in connection with a rotation knob 28′ which may besubstantially identical to rotation knob 28 described above, except thatrotation knob 28′ is configured to support a articulation knob 1730 asshown. As can be seen in FIG. 66, the articulation knob 1730 may includea thumb tab 1732 that is attached to a pivot shaft 1734 that extendsthrough a hole 1736 in the rotation knob segment 28 a′. The pivot shaft1734 may have a squared portion 1735 that is adapted to be non-rotatablyreceived in a corresponding square hole 1752 in a cam disc 1750. Thetranslation member 138 may have an upstanding arm portion 540 that has anotch 542 therein that is sized to receive a tab (not shown) formed onthe sensor cylinder (not shown) as was described above. The distal endof translation member 138 may include an arm 546 which includes anopening 548 configured to receive a finger 164 (not shown in FIGS. 65and 66) extending from the proximal end of articulation link 123 (notshown in FIGS. 65 and 66) as was described above. See FIGS. 4 and 11. Apin 166 that may be constructed from a non-abrasive material, e.g.,Teflon® or metal that has been coated with Teflon®, is secured totranslation member 138 and dimensioned to be received within anarcuate-shaped cam slot 1754. Thus, as the actuation knob 1730 isrotated, the pin 166 is driven longitudinally either in the proximaldirection “PD” or the distal direction “DD”, depending upon thedirection in which the actuation knob 1730 is rotated. The longitudinaldisplacement of the pin 166 is illustrated in the series of FIGS. 67-69.For example, FIG. 67 illustrates the position of the cam disc 1750 andpin 166 when the disposable loading unit has been articulated to theleft. FIG. 68 illustrates the position of the cam disc 17650 andarticulation pin 166 when the disposable loading unit has not beenarticulated (e.g., is axially aligned with the elongated body) and FIG.69 illustrates the position of the cam disc 1750 and articulation pin166 when the disposable loading unit has been articulated to the right.In some embodiments, the arcuate cam slot 1754 may be shaped such thatthe ramp angle thereof relative to pin 166 throughout the entireactuation sequence is relatively low (under 15 degrees) which may resultin an effective articulation lock.

FIGS. 70 and 71 illustrate another unique and novel articulationmechanism 1820 and unique and novel lockable rotation system 1850 thatmay be used in connection with a stapling apparatus 1810 that may employa disposable loading unit. The articulation mechanism 1820 isconstructed to axially advance the translation member 138 to ultimatelyresult in the longitudinal actuation of an articulation link 123 (notshown in FIGS. 70 and 71) that is coupled to the translation member 138.As can be seen in FIGS. 70 and 71, the articulation mechanism 1820 maybe used in connection with a handle housing 36″ that is formed fromhandle segments (handle segment 36 a″ is shown in FIGS. 70 and 71 withit being understood that another handle segment shaped to mate withhandle segment 36 a″ is employed to form handle housing 36″). In variousembodiments, the articulation mechanism 1820 is mounted to a rotatableshroud 1830 that has a flanged proximal end 1832 that is adapted to bereceived in an annular groove 1834 formed in the handle housing 36″ suchthat the rotatable shroud 1830 may be selectively rotated about axis“L-L” relative to handle housing 36″ as will be discussed in furtherdetail below. Although not shown in FIGS. 70 and 71, the elongatedmember 14 and casing 124 described above in connection with otherembodiments may be attached to the rotatable shroud 1830 by radialprojections 132 formed on the distal end of rotatable shroud 1830. SeeFIG. 70. Projections 132 and openings 128 in casing 124 fixedly securerotatable shroud 1830 and elongated body 14 in relation to each other,both longitudinally and rotatably. Rotation of rotatable shroud 1830with respect to handle housing 36″ thus results in correspondingrotation of elongated body 14 with respect to handle housing 36″.

As can be seen in FIGS. 70 and 71, the articulation mechanism 1820 maycomprise an articulation ring 1822 that is threadedly attached to aseries a of threads 1836 provided on the rotatable shroud 1830. Thetranslation member 138 may have an upstanding arm portion 540 that has anotch 542 therein that is sized to receive a tab (not shown) formed onthe sensor cylinder (not shown) as was described above. The distal endof translation member 138 may include an arm 546 which includes anopening 548 configured to receive a finger 164 (not shown in FIGS. 70and 71) extending from the proximal end of articulation link 123 (notshown in FIGS. 70 and 71) as was described above. See FIGS. 4 and 11. Apin 166 that may be constructed from a non-abrasive material, e.g.,Teflon® or metal that has been coated with Teflon®, is secured totranslation member 138 and dimensioned to be received within an annularslot 1825 formed in the articulation ring 1822. Thus, as thearticulation ring 1822 is threadedly advanced on the rotatable shroud1830 in the proximal direction “PD”, the pin 166 also drives thetranslation member 138 (and the articulation link 123) in the proximaldirection “PD” to cause the disposable loading unit to articulate in theright hand direction. Likewise, as the articulation ring 1822 isthreadedly advanced on the rotatable shroud 1830 in the distal direction“DD”, the pin 166 also drives the translation member 138 (and thearticulation link 123) in the distal direction “DD” to cause thedisposable loading unit to articulate in the left hand direction.

The embodiment depicted in FIGS. 70 and 71 also has a unique and novellockable rotation system 1850 which may include a lockable knob 1852that consists of two knob segments 1852 a that are coupled together byscrews, glue, snap features, posts, etc. over the distal end of thehandle housing 36″ such that the lockable knob 1852 is rotatably andaxially supported on the distal end of the handle assembly 36″. As canalso be seen in FIGS. 70 and 71, the distal end of the handle housing36″ has a first lock flange 1860 with a first set of radial gear teeth1862 formed thereon. The lockable knob 1852 may also have an inwardlyextending second lock flange 1854 that has a second set of radial gearteeth 1856 formed thereon. The second set of radial gear teeth 1856 arelocated in confronting relationship with the first set of radial gearteeth 1862 on the first lock flange 1860 such that the second radialgear teeth 1856 may selectively mesh with the first radial gear teeth1862. A lock spring 1870 may be used to bias the lock knob 1852 in thedistal direction “DD” to bring the second set of radial gear teeth 1856into meshing engagement with the first set of radial gear teeth 1862. Ascan also be seen in FIGS. 70 and 71, the proximal end 1831 of therotatable shroud 1830 has a rotation spline 1837 formed thereonconfigured to mesh with an inwardly extending toothed flange 1858 formedon the distal end of the lockable knob 1852. Those of ordinary skill inthe art will understand that the rotation spline 1837 and toothed flange1858 serve to rotatably affix the lockable knob 1852 to the rotatableshroud 1830 while enabling the lockable knob 1852 to move axiallyrelative to the rotatable shroud 1830. Thus, to rotate the rotatableshroud 1830 (and the elongate body 14 and disposable loading unitaffixed thereto), the clinician biases the lockable knob 1852 in theproximal direction “PD” to disengage the second set of radial gear teeth1856 from the first set of radial gear teeth 1862 which thereby permitsthe lockable knob 1852 to rotate about longitudinal axis “L-L” relativeto handle housing 36″. As the lockable knob 1852 is rotated, therotatable shroud 1830 also rotates with the lockable knob 1852 by virtueof the engagement between the toothed flange 1858 and the rotationspline 1837. After the clinician has rotated the rotatable shroud 1830to the desired position, he or she then releases the lockable knob 1852.When the lockable knob 1852 is released, the spring 1870 biases thesecond set of radial gear teeth 1856 into meshing engagement with thefirst set of radial gear teeth 1862 to retain the rotatable shroud 1830in that position. Thus, such unique and novel arrangements solve theproblems associated with rotatable knobs and articulation mechanismsemployed in prior surgical instruments that are used in connection withdisposable loading units. In particular, after the disposable loadingunit and elongated body has been inserted into the patient, theclinician may rotate the disposable loading unit about the longitudinalaxis “L-L” relative to the handle assembly 12″ to a desired orientationand then lock it in that position. Thereafter, the clinician may thenarticulate the disposable loading unit to the left side or right side ofthe longitudinal axis. In the embodiments described immediately above,the threaded engagement between the articulation ring and the rotatableknob serves to lock the disposable loading unit in the desiredarticulated position. As in indicated above, in prior surgicalinstruments that employ a rotatable knob that has an articulation knobaffixed thereto, the rotation knob may move as the clinician actuatesthe articulation lever making it difficult to accurately position thedisposable loading unit.

FIGS. 72 and 73 illustrate another unique and novel articulationmechanism 1920 mounted within a rotatable knob 28″ of the type ofconstruction and operation described hereinabove. In this embodiment,the articulation mechanism 1920 may comprise an outer articulation ring1922 that has a thrust flange 1924 formed thereon configured to bereceived in an annular groove 1930 formed in the rotatable knob 28″ forrotatably supporting the outer articulation ring 1922 in the rotatableknob 28″such that the outer articulation ring 1922 is free to rotaterelative to the rotatable knob 28″, but it cannot move axially relativethereto. In various embodiments, the proximal end 1923 of the outerarticulation ring 1922 may have radial gear teeth 1926 formed thereonfor meshing engagement with a spur gear 1940 that is attached to anarticulation knob 1942. As can be seen in FIG. 73, the articulation knob1942 has a shaft 1944 attached thereto that is rotatably received in athrough hole 1943 in the rotatable knob 28″ and is non-rotatablyattached to the spur gear 1940 such that rotation of the articulationknob 1942 causes the spur gear 1940 to rotate. As the spur gear 1940 isrotated, the outer articulation ring 1922 is also rotated about thelongitudinal axis “L-L”. Those of ordinary skill in the art willunderstand that the outer articulation ring 1922 may be selectivelyrotated in the clockwise “CCW” or counterclockwise “CCW” directionsabout the longitudinal axis L-L, depending upon the direction ofrotation of the articulation knob 1942.

As can also be seen in FIG. 72, the outer articulation ring 1922 has aninternal thread 1928 formed therein for threaded engagement with aninner articulation ring 1950. In this embodiment, the translation membercomprises a metal link 1960 that is attached or pinned to the innerarticulation ring 1950 by a pin 1952 or other fastener arrangements. Themetal link 1960 is constrained to only move axially in the proximaldirection “PD” and “distal direction “DD” because it is received withinan axial groove 1962 formed in the rotatable knob 28”. The distal end ofthe metal link 1960 includes an opening 1964 configured to receive afinger 164 extending from the proximal end of articulation link 123.Thus, rotation of articulation knob 1942 will result in the axialmovement of the articulation link 123 in the proximal direction “PD” ordistal direction “DD” depending upon the direction of rotation of thearticulation knob 1942. When the articulation link 123 is advanced inthe distal direction “DD”, it will result in the disposable loading unitbeing articulated to left and when the articulation link is pulled inthe proximal direction “PD”, it will result in the disposable loadingunit being articulated to the right as was discussed above. Those ofordinary skill in the art will appreciate that the threaded engagementbetween the inner articulation ring 1950 and the outer articulation ring1922 will serve to retain the articulation link (and, ultimately thedisposable loading unit) in the desired articulated position until thearticulation knob is again rotated. It will be further appreciated thatthe desired knob rotation can be set by the gear ratio and thread pitch.

FIGS. 74 and 75 depict an another alternative articulation mechanism1920′ that employs an inner articulation ring 1922′ that is identical toarticulation ring 1922 described above, except that articulation ring1922′ has a cam slot 1970 therein instead of the inner threads 1928. Ascan be seen in FIGS. 74 and 75, the metal link 1960 has an articulationpin 1966 attached thereto that rides in the cam slot 1970 in the innerarticulation ring 1922′. Thus, as the inner articulation ring 1922′ isrotated by means of the articulation knob 1942 as was described above,the cam slot 1970 and articulation pin 1966 received therein drives themetal link 1960 in the proximal direction “PD” and the distal direction“DD” which results in the axial movement of the articulation link 123 inthose directions as was described above.

When using prior surgical stapling devices that are adapted for use withdisposable loading units, often times the control rod gets inadvertentlyadvanced out of the end of the casing of the elongated body prior toattachment of the disposable reload unit. When that happens, and thedisposable reload unit is attached to the apparatus, the reload unitcannot be fired. Instead, the clinician must first retract the controlrod before attaching the reload unit. This occurrence can engenderconfusion and results in unnecessary downtime during the operation. Inaddition, during the firing sequence, the firing bar may become jammedrequiring the clinician to retract the firing bar which can be difficultat times depending upon the nature of the jam. The embodiment of thesurgical stapling apparatus 2010 of the present invention addresses suchproblems.

More particularly and with reference to FIG. 76, the surgical staplingapparatus 2010 may be substantially similar in construction as thevarious instruments described above, except for the unique and novelretraction system 2020 as will be described in detail below. Thosecomponents that are the same as the components employed in theabove-mentioned embodiments will be labeled with the same elementnumbers and those of ordinary skill in the art can refer to thedisclosure set forth hereinabove that explains their construction andoperation.

In one embodiment, the surgical stapling apparatus 2010 may include ahandle assembly 2012 that has an elongated body 14 that is operablycoupled to the handle assembly 2012 and protrudes distally therefrom. Adistal end of the elongated body 14 may be coupled to an articulatabledisposable loading unit 16 (or a non-articulatable disposable loadingunit). The disposable loading unit 16 may include a tool assembly 17that is selectively articulatable about an articulation axis “A1-“A1” byarticulation motions transferred thereto by the elongated body 14 as isknown. See FIG. 76. In various embodiments, the proximal end of theelongated body 14 is coupled to a rotatable knob 28 that is coupled tohandle housing 2036. As can be seen in FIGS. 76 and 77, the handlehousing 2036 may be formed from a right housing segment 2036 a and aleft housing segment 2036 b that are attached together.

As shown in FIGS. 76-78, the right hand housing segment 2036 a may havea removable cover 2040 that is coupled to the right housing segment 2036a by snaps, screws, pin inserts or a releasable detent post insertedinto a boss. As will be discussed in further detail below, thisembodiment also employs a release plate 64 (FIG. 81) of the type andconstruction described above which has a coupling rod 60 attachedthereto. The coupling rod 60 extends through an elongated retract slot34 b in the left housing segment 2036 b (FIG. 76) as well as through anelongated retract slot 34 a in the removable cover 2040 (FIG. 77) tohave retractor knobs 32 a, 32 b attached thereto as was described above.The right housing segment 2036 a further has a retract slot 34 a′ formedtherein that corresponds with the retract slot 34 a in the removablecover 2040 when the removable cover 2040 is attached thereto by snapfeatures, adhesive, screws, etc. In this embodiment, the right housingsegment 2036 a may have a pair of spaced elongated guide ribs 2050formed therein that serve to define an elongated retract passage 2052therebetween. Also in various embodiments, a retract slide member 2060may be received on the coupling rod 60 and be constrained to axiallymove in the distal direction “DD” and proximal direction “PD” within theelongated retract passage 2052. The retraction system 2020 may furtherinclude a cable slide 2070 that is also constrained to movelongitudinally within the retract passage 2052 as can be seen in FIGS.79 and 84-86. The proximal end 2072 of the cable slide 2070 may have anotch 2074 therein to enable a proximal end 2082 of a retract cable 2080to be pinned or otherwise attached thereto. A distal end 2084 of theretract cable 2080 may be attached to a proximal end 2092 of aretraction spring 2090. The distal end 2094 of the retraction spring2090 may be attached to a retraction spring post 2096 formed on theright housing segment 2036 a. See FIGS. 78 and 83-85. The retractioncable 2080 may be journaled on a retract pulley 2100 that is rotatablysupported on a pulley post 2102 formed on the right housing segment 2036a.

In various embodiments, the retraction system 2020 may be configured toenable the control rod 52 to be automatically retracted at the end ofthe firing sequence or, if desired, manually retracted. For example, ascan be seen in FIG. 83, a cocking lug 2110 may have a hollow cavity 2111therein and be attached to the cable slide 2070 by a clevis-like lugmount 2112 and pin 2114 that is received within the hollow cavity 2111.As can be seen in FIG. 83, the cocking lug 2110 may further have aninner end portion 2116 that is arranged to be adjacent to the removablecover 2040 and also have a relieved area or notch 2118 formed therein. Alug spring 2120 configured as shown in FIGS. 78 and 83, may be journaledon the pin 2114 to bias the cocking lug 2110 about the pin 2114 in thecounterclockwise “CCW” direction as shown in FIG. 83. The retractionsystem 2020 may further include a retraction lock assembly 2130.

The retraction lock assembly 2130 may include a lock member 2132 that ispivotally pinned to the removable cover 2040 by a lock pin 2134. A lockspring 2140 configured as shown in FIGS. 82 and 83, may be journaled onthe lock pin 2134 and attached to the cover 2040 by a screw 2142 orother suitable fastener such that the lock spring 2140 is biased in thecounterclockwise “CCW” direction in FIG. 83. As can further be seen inFIG. 83, the lock member 2132 is configured to protrude through a window2044 in the cover 2040 and has a notched proximal end 2136 adapted toengage a notch 2046 in the cover 2040. See FIG. 83. The lock member 2132may have a distal end 2138 that is adapted to retainingly engage a notch2076 in the proximal end 2072 of the cable slide 2070.

Operation of the surgical stapling apparatus 2010 will now be describedwith reference to FIGS. 84-88. FIG. 84 illustrates the surgical staplingapparatus 2010 in an initial “pre-fired” position wherein the retractknob 32 a and the cocking knob 2110 (FIG. 80) are in the “pre-fired”position located at the proximal end of the handle housing 2036. Priorto commencing the firing sequence, the clinician may push the cockinglug 2110 in the distal direction “DD” to the cocked position shown inFIG. 85. As can be seen in that Figure, when the cocking lug 2110 is inthe cocked position, the retraction spring 2090 is stretched and servesto store retraction energy therein. After the cocking lug 2110 has beenmoved to the cocked position, the clinician may press the firing button82 (as was discussed above) and then commence the firing sequence byratcheting the movable handle 24. As the clinician advances theactuation shaft 46 in the distal direction “DD” by ratcheting themovable handle 24, the retract knobs 32 a, 32 b move distally with theactuation shaft 46 until they reach the position shown in FIG. 86 whichis prior to the end of the firing stroke (i.e., the control rod 52 hasbeen advanced as far as it can go in the distal direction to cause thedisposable reload unit to be completed fired). If the clinician wishesto manually retract the control rod 52 prior to reaching the finalfiring stroke (at any time during the firing sequence), the cliniciansimply biases the cocking lug 2110 in the clockwise “CW” direction shownin FIG. 87 which causes the cocking lug 2110 to bias the lock member2132 in the clockwise direction “CW” to thereby cause the distal end2138 to move out of the locking notch 2076 in the cable slide 2070 tothereby permit the cable slide 2070 to move in the proximal direction“PD” under the force of the retraction spring 2090 and thereby force theretract slide 2060 in the proximal direction “PD”. Because the retractbar 60 extend through the retract slide 2060 and is attached to theretraction plate 64, the retract bar 60 causes the retract plate 64 toretract the actuation shaft 46 (and the control rod 52) by virtue of itsattachment to the actuation shaft 46.

If the clinician does not wish to manually actuate the retraction system2020, the clinician may keep ratcheting the movable handle 24 until thefiring sequence is completed. When the actuation shaft 46 has beendistally advanced to its distal most position at the completion of thefiring sequence, (FIG. 88) the retract slide 2060 biases the lock member2132 to the position shown in FIG. 88 such that the distal end 2138 ismoved out of retaining engagement with the notch 2076 in the cable slide2070 which permits the cable slide 2070 to move to the proximal mostretracted position under the force of the retraction spring 2090. Thus,when the retract knob 32 a reaches the fully fired position, it causesthe retract system 2020 to automatically retract the actuation shaft 46and control rod 52.

Those of ordinary skill in the art will readily appreciate that theseembodiments serve to avoid the problem of the control rod 52 not beingfully retracted to a position wherein another disposable reload unit maybe attached to the stapling apparatus. In addition, the retractionspring serves to assist the clinician in retracting the control rod,should it be necessary to do so during the firing sequence.

FIG. 89 illustrates an alternative disposable loading unit 2216 that hasan elongated housing portion 250′ that may include an upper housing half(not shown) and a lower housing half 252′. The distal end of the housing250′ is attached to a tool assembly 17 (FIG. 76) and removablyattachable to the elongated body 14. Housing halves define a channel253′ for slidably receiving axial drive assembly 212 therein. As will bediscussed further below, the drive assembly 212 includes an elongateddrive beam 266 including a distal working head 268 and a proximalengagement section 270. Drive beam 266 may be constructed from a singlesheet of material or, preferably, from multiple stacked sheets.Engagement section 270 may include a pair of engagement fingers 270 aand 270 b which may be dimensioned and configured to mountingly engage apair of corresponding retention slots 272 a formed in drive member 272.Drive member 272 may include a proximal porthole 274 configured toreceive the distal end of control rod 52 when the proximal end ofdisposable loading unit 2216 is engaged with elongated body 14 ofsurgical stapling apparatus 10. In this embodiment, at least one, andpreferably a pair of, energy storing members 2220 are also supported inthe housing 250′ as shown. Energy storing members 2220 may comprisecompression springs 2222. As control rod 52 is axially advanced in thedistal direction “DD”, the drive member 272 and drive beam 266 aredriven in that direction compressing the springs 2222 (i.e., storingretraction energy therein). After the firing sequence has been completedor, if during the firing sequence it becomes necessary to retract thedrive beam 266, the compressed springs 2222 will release the storedretraction energy and serve to assist in the retraction processes byreleasing their stored energy to bias the drive beam 266 and drivemember 272 in the proximal direction “PD”.

Prior instruments, such as those disclosed in U.S. Pat. No. 5,865,361suffer from the inability to be fired in thicker tissues (e.g., tissueswith thicknesses greater than 3.5 mm) due to the increased loads appliedto the firing system. Such increased loads can, for example, increasethe likelihood that the firing system will fail when the knife is stillin the anvil and may therefore require that the end effector be cut offof the tissue. Such failure mode can have serious patient injuryconsequences. Various embodiments of the present invention are directedto improved actuation transfer mechanisms or assemblies that areconstructed to act as a fail safe “fuse” or device that would preventadvancement of the actuation shaft 46 (e.g., prevent transfer ofactuation motions to the disposable loading unit) when the firing loadresulting from thick tissue exceeds a predetermined magnitude.

FIG. 90 illustrates one actuation transfer assembly 100 that includes adriving pawl 42′ that has a pawl body portion 102 that has rackengagement member or tooth 43 that is attached to or formed on the pawlbody portion 102 at an attachment area generally designated as 104. Inthe embodiment depicted in FIG. 90, an undercut or weakened area 45 isformed along at least a portion of the attachment area 104. Thecharacteristics of the undercut or weakened area 45 may be sized suchthat the tooth 43 will shear off of the driving pawl 42′ or otherwiseassume a non-driving position when the firing load attains apredetermined maximum value to thereby prevent advancement of theactuation shaft 46—even though the manually actuatable handle member 24continues to be actuated. In various embodiments, the predeterminedmaximum value may be selected so that the tooth 43 shears off orotherwise assumes a non-driving position before any other componentswould fail or otherwise become inoperable due to the resistanceexperienced by the drive beam due to jamming or other restriction.

Another pawl arrangement is depicted in FIG. 91. As can be seen in thatFigure, the pawl 42″ has a pawl body 106 a width “W” and the engagementtooth 43 has a width “W′” that is less than “W”, such that theengagement tooth 43 will shear or otherwise fail when the firing loadexceeds a predetermined magnitude to prevent the actuation shaft 46 frombeing further advanced—even though the manually actuatable handle member24 continues to be actuated. In various embodiments, the pawls 42′, 42″may be fabricated (molded, machined, etc.) from a single material. Inother embodiments, the engagement tooth 43 may be formed separately fromthe pawl body 106 and may be attached thereto by a shear pin (not shown)or other means such as adhesive to support the engagement tooth 43 in aposition for driving engagement with the actuation shaft 46 under normalloads, yet shear off to permit the tooth 43 to pivot to a non-engagedposition when the firing load exceeds a predetermined magnitude.

FIG. 92 illustrates another actuation transfer assembly 100′ thatincludes an actuation shaft 46′ that is designed to fail when the firingload exceeds a predetermined magnitude. In this embodiment, an undercutarea 108 is provided between adjacent teeth 49 and is sized to form ashear area length “SL” that will facilitate in the shearing of the tooth49 or otherwise permit the tooth 49 to drivingly disengage from thetooth 43 or permit the tooth 43 on the pawl 42 to slip over the tooth 49on the rack 48′ when the firing load attains or exceeds thepredetermined magnitude described above. In an alternative embodimentillustrated in FIG. 93, the actuation bar 46″ has a width “WB” and eachtooth 49 has a width “WT” that may be less than the width “WB”. Thewidth “WT” may be sized to enable the teeth 49 to shear off of theactuation shaft 46″ or otherwise fail or drivingly disengage from thetooth 43 on the pawl 42 when the firing load attains or exceeds apredetermined magnitude as was discussed above. Further, the transferassembly may be sized to buckle or flex under appropriate load so as todisengage the teeth from the pawl at a predetermined load. The teeth onthe pawl and the rack in various embodiments may be designed at a verywide range of minimum failure loads depending upon the degree of safetydesired. Such minimum failure loads may be attained by altering thegeometry, design and/or materials from which the teeth, adhesive, shearpins, etc. are made.

Those of ordinary skill in the art will appreciate that the foregoingdescribed actuation transfer assembly arrangements of the presentinvention represent vast improvements over prior surgical instrumentsthat are adapted to actuate disposable reload units. In particular, suchactuation transfer assemblies of the present invention will prevent theclinician from advancing the cutting and stapling components in thereload unit when the reload unit has encountered firing forces thatmight lead to the jamming and/or failure of the cutting and staplingcomponents to advance completely through the tissue clamped in the unit.In prior units, the clinician might be unaware that the thickness of thetissue clamped in the unit was too great to complete the procedure andunwittingly continue to advance the cutting and stapling components inthe unit by actuating the handle until the handle assembly exploded orotherwise failed destroying the ability to retract the knife. If thecomponents become jammed, the clinician may be unable to retract thecomponents and therefor have to cut the unit from the tissue. Thevarious arrangements of the present invention described above, addresssuch problems.

These unique and novel features may also be effectively employed withother surgical cutting and stapling apparatuses that use a driving pawlarrangement. For example, FIGS. 93A and 93B illustrate the use of a twopart pawl arrangement 2000 that can be effectively employed with thesurgical instruments disclosed in U.S. patent application Ser. No.11/821,277, to Chad P. Boudreaux and Jeffrey S. Swayze, filed Jun. 22,2007, entitled Surgical Stapling Instruments, the disclosure of which isherein incorporated by reference in its entirety. In particular, the twopart pawl assembly 2000 may comprise a pawl body 2010 that may beconfigured and otherwise operated as described in the aforementionedpatent application except that, in this embodiment, the tooth portion2020 is pivotally or otherwise movably coupled to the pawl body 2010.The tooth portion 2020 may be normally supported in a drivingorientation (FIG. 93A) by a shear pin 2030 or other suitable arrangementsuch as adhesive, etc. that is selected to shear or otherwise fail whenthe firing member 2040 thereof encounters a predetermined amount offiring load or resistance during firing. FIG. 93A illustrates the tooth2020 in driving engagement with the firing member 2040. FIG. 93Billustrates the position after the firing member 2040 has encountered aresistance that exceeds the predetermined firing load which therebycaused the shear pin 2030 to shear off permitting the tooth 2020 topivot to a non-engaged position. Thus, when in the non-engaged position,the firing member 2040 cannot be advanced distally even though thefiring trigger continues to be actuated.

FIGS. 94-97 illustrate a unique and novel articulatable disposablereload unit 3016 that may be employed with the surgical staplingapparatus 10 or any of the other various surgical stapling apparatusesdescribed herein above. Referring to FIG. 96, the disposable loadingunit 3016 may include a tool assembly 17 that has an anvil assembly 20and cartridge assembly 18. Anvil assembly 20 may include anvil portion204 that may have a plurality of staple deforming concavities (notshown) formed in the undersurface thereof. A cover plate 208 may besecured to a top surface of anvil portion 204 to define a cavitytherebetween. The cavity may be dimensioned to receive a distal end ofan axial drive assembly 212. A longitudinal slot 214 extends throughanvil portion 204 to facilitate passage of retention flange 284 of axialdrive assembly 212 into the anvil cavity. A camming surface 209 formedon anvil portion 204 may be positioned to engage axial drive assembly212 to facilitate clamping of tissue between the anvil assembly 20 andthe cartridge 18. A pair of pivot members 211 formed on anvil portion204 may be positioned within slots 213 formed in carrier 216 to guidethe anvil portion 204 between the open and clamped positions.

In various embodiments, cartridge assembly 18 may include a carrier 216which defines an elongated support channel 218. See FIG. 96. Elongatedsupport channel 218 may be dimensioned and configured to receive astaple cartridge 220. Corresponding tabs 222 and slots 224 formed alongstaple cartridge 220 and elongated support channel 218 may function toretain staple cartridge 220 within support channel 218. A pair ofsupport struts 223 may be formed on staple cartridge 220 such that theyare positioned to rest on side walls of carrier 216 to further stabilizestaple cartridge 220 within support channel 218.

Staple cartridge 220 may include retention slots 225 for receiving aplurality of fasteners and pushers as is known. A plurality of spacedapart longitudinal slots 230 extend through staple cartridge 220 toaccommodate upstanding cam wedges 232 of an actuation sled 234. Acentral longitudinal slot 282 extends along the length of staplecartridge 220 to facilitate passage of a knife blade 280. Duringoperation of surgical stapler 10, actuation sled 234 translates throughlongitudinal slots 230 of staple cartridge 220 to advance cam wedges 232into sequential contact with pushers operably supported in the slots225, to cause pushers (not shown) to translate vertically within slots225 and urge the fasteners associated with the pushers (not shown) fromslots 225 into the staple deforming cavities of the anvil assembly 20.

Various embodiments may include a mounting assembly 202 that maycomprise upper and lower mounting portions 236 and 238. In oneembodiment, the upper mounting portion 236 may be provided with a pairof trunnions 237 that are adapted to be pivotally received within holes219 in the side walls of the carrier 216. A pair of anti-bucklingsprings 241 may be supported in corresponding cavities formed in themounting assembly 202 to provide support to the laminated knife assemblywithin the mounting assembly 202. A proximal portion of mountingassembly 202 may be non-rotatably mounted in a distal body adapter 243as shown in FIG. 96.

Housing portion 200 of disposable loading unit 3016 may include an upperhousing half 250 and a lower housing half 252. The proximal end ofhousing half 250 may include engagement nubs 254 for releasably engagingelongated body 14 (FIG. 94) and an insertion tip 193. Nubs 254 form abayonet type coupling with the distal end of body 14 as described inU.S. Pat. No. 5,865,361.

As can also be seen in FIG. 96, axial drive assembly 212 may include anelongated drive beam 266 including a distal working head 268 and aproximal engagement section 270. Drive beam 266 may be constructed froma single sheet of material or, preferably, from multiple stacked sheets.Engagement section 270 may include a pair of engagement fingers 270 aand 270 b which may be dimensioned and configured to mountingly engage apair of corresponding retention slots 272 a formed in drive member 272.Drive member 272 may include a proximal porthole (not shown) configuredto receive the distal end 276 of control rod 52 (described above) whenthe proximal end of disposable loading unit 3016 is engaged withelongated body 14 of surgical stapling apparatus 10.

The distal end of drive beam 266 may be defined by a vertical supportstrut 278 which supports a knife blade 280, and an abutment surface 283which engages the central portion of actuation sled 234 during astapling procedure. Surface 285 at the base of surface 283 may beconfigured to receive a support member 287 slidably positioned along thebottom of the carrier 216. Knife blade 280 may be positioned totranslate slightly behind actuation sled 234 through a centrallongitudinal slot 282 in staple cartridge 220 to form an incisionbetween rows of stapled body tissue. To provide support to the drivebeam 266 within the housing 200 as the drive beam 266 is advancedaxially, a blade stabilizing member 290 may be mounted within thehousing 200.

A retention flange 284 may project distally from vertical strut 278 andmay support a pair of cylindrical cam rollers 286 at its distal end. Camrollers 286 may comprise pressed in or welded in pins and be dimensionedand configured to engage camming surface 209 on anvil body 204 to clampanvil portion 204 against body tissue. A pair of springs 207 may beprovided between the proximal end of the anvil portion 204 and the uppermounting portion 236 to bias the anvil assembly 20 to a normally openposition.

The reload unit 3016 depicted in FIGS. 94-97 employs a “passive”articulation arrangement. As can be seen in those FIGS., the reload unit3016 includes a flexible articulation member 300 that is coupled to ahousing assembly 200 by, for example, a proximal body collar 301. Theflexible articulation member 300 has a body portion 301 that may befabricated from polyethylene, poly propylene or other suitablematerials, for example, and include a plurality of kerfs 302 separatedby ribs 304. In various embodiments, the kerfs 302 and ribs 304 may beequally spaced along the flexible articulation member 300 therebypromoting a continuous bend radius when the flexible articulation memberis articulated. A flexible articulation member 300 having multiple bendradii may be achieved by providing unequal spacing between the kerfs 302and the ribs 304. For example, such arrangement may be achieved byspacing the ribs 304 more closely at one end and farther apart at theother end. As will be appreciated by those of ordinary skill in the art,increasing the spacing of the kerfs 302 and/or the ribs 304 reduces thebend radius of the section having increased spacing, more closelyapproximating a pivot point bend connection. Conversely spacing thekerfs 3402 and/or ribs 304 more closely results in a more gradual bend,having a larger bend radius. Alternatively, the flexible articulationmember 300 may be fabricated from a combination of materials, theexterior of which may be slotted stainless steel, which will function ina similar manner to the above-mentioned plastics and polymericmaterials.

In the embodiment illustrated in FIGS. 94-97, the kerfs 302 compriseannular grooves that extend at least partially around the perimeter ofthe flexible articulation member 300. The kerfs 302 preferably, however,comprise semi-annular grooves which are separated by a centrallongitudinal spine 306 passing down the longitudinal axis L-L of theflexible articulation member 300 such that a first plurality of ribs areformed on one lateral side of the spine 306 and a second plurality ofribs are formed on another lateral side of the spine 306. This spine 306assists in providing stiffening to the flexible articulation member 300and accommodates a slot 310 therethrough for receiving the surgicaltools, such as the drive assembly 212. The longitudinal spine 306 mayrun the entire longitudinal length of the flexible articulation member300. The flexible articulation member 300 may also include a pair ofside slots 314 passing through each rib 304 on each lateral side forreceiving a corresponding articulation plate 320. See FIG. 96. Sucharticulation plates 320 may be fabricated from a material that isrelatively inelastic. That is, the plates 320 may be fabricated from amaterial that retains its position after bending. Articulation plates320 may be fabricated from materials such as, for example, lead, copper,stainless steel, titanium, etc.

The disposable loading unit 3016 is sized for insertion, in anon-articulated state as depicted in FIGS. 94 and 95, through a trocarcannula passageway to a surgical site in a patient (not shown) forperforming a surgical procedure. For example, the disposable loadingunit 3016 may be sized to be inserted through a gastroscope orcolonoscope. After the tool assembly 17 portion of the disposableloading unit 3016 has been inserted through the trocar cannulapassageway, the clinician can move the tool assembly 17 to a desiredarticulated orientation by “passively” bringing the tool assembly 17into contact with the organ or other portion of the body or anothermedical instrument 330 (e.g., graspers—FIG. 97) to apply an externalforce to the tool assembly 17 to cause it to articulate within a planerelative to the housing portion 200 of the disposable loading unit 3016.The person of ordinary skill in the art will appreciate once the toolassembly 17 is articulated to the desired position, the articulationplates 320 serve to retain the tool assembly 17 in that configuration.The tool assembly 17 can be articulated through an angle “PA” asillustrated in FIG. 97.

FIGS. 98-101 illustrate another reload unit 3016′ embodiment of thepresent invention. Reload unit 3016′ is substantially identical toreload unit 16, except that reload unit 3016′ is constructed to bepassively articulated as well as actively articulated. As can be seen inFIGS. 98 and 99, the reload unit 3016′ includes a first articulationjoint 340 that is formed from a mounting assembly 202′ that includes adistal portion 206 and a proximal portion 226 that is pivotally coupledthereto. In various embodiments, the distal portion 206 includes anupper mounting portion 208 and a lower mounting portion 210. A pivot pin244 may be formed on each of the mounting portions 206′, 208′ to definea pivot axis “A1” which may be substantially perpendicular to thelongitudinal axis “L’L’ of the disposable reload unit 3016′. Theproximal portion 226 of the mounting assembly 202′ may comprise an uppermounting portion 236′ and a lower mounting portion 238′. The distalportion 206 of the mounting member 202′ and the proximal portion 226 ofthe mounting member 202′ may be pivotally coupled together by a pair ofcoupling members 246. Coupling members 246 each have a hole 247therethrough for receiving a corresponding pin 244 therethrough. Theproximal end 248 of each coupling member 246 is configured to beinterlockingly received in a corresponding groove 251 formed in theupper mounting portion 236′ and lower mounting portion 238′. Theproximal portion 226 of mounting assembly 202′ may be non-rotatablymounted in a distal body adapter 243 as shown in FIG. 99. Housingportion 200 of disposable loading unit 3016′ may include an upperhousing half 250 and a lower housing half 252. The proximal end ofhousing half 250 may include engagement nubs 254 for releasably engagingelongated body 14 (not shown in FIG. 99) and an insertion tip 193. Nubs254 form a bayonet type coupling with the distal end of body 14 whichwill be discussed in further detail below. Housing halves 250 and 252define a channel 253 for slidably receiving axial drive assembly 212therein. A pair of springs 207 may be provided between the proximal endof the anvil portion 204 and the upper mounting portion to bias theanvil assembly 20 to a normally open position.

This embodiment may also employ a flexible articulation member 300′ thatmay be substantially similar to the flexible articulation member 300described above, except for the differences noted below. The distal endof the flexible articulation member 300′ may be non-rotatably affixed tothe distal body adapter 243 and the proximal end of the flexiblearticulation member 300′ may be non-rotatably affixed to the proximalbody collar 301 that is attached to the housing portion 200. In thisembodiment, an articulation link 256′ may be employed to also enable theuser to actively articulate the tool assembly 17. Articulation link 256′may have an elongated flexible wire portion 450 that terminates in adistal hook portion 452. The wire portion 450 may be received in a lumen420 in the flexible articulation member 300′. The hooked end 452 may bepinned between distal portion 206 and lower mounting portion 210 by apin affixed therebetween. See FIG. 99. The flexible wire portion 450 maybe attached to a rod portion 451 that has a tab or other hook portion258′ that is configured for hooking engagement with a distal hook 165formed on the distal end of the first articulation link 123 in a knownmanner as described in U.S. Pat. No. 5,865,361. See FIG. 10. Such reloadunit 3016′ arrangement may be passively articulated using flexiblearticulation member 300′ about angle “PA” in the manner described abovethrough a range of travel “PA” or, if desired, the clinician mayactively articulate the tool assembly 17 thereof about the firstarticulation axis “A1-A1” through a range of travel “AA” by activatingthe articulation lever 30 in the manner described in U.S. Pat. No.5,865,361. See FIG. 101.

FIGS. 102-104 illustrate another reload unit 3016″ embodiment of thepresent invention. Reload unit 3016″ may be substantially identical toreload unit 3016′, except that reload unit 3016″ is constructed with twoactive articulation links 256R, 256L that enables the articulation link300 to be actively pulled on one side while being actively pushed on theopposite side. As can be seen in FIG. 103 articulation links 256R and256L may have a distal plate portion 430 that is sized to extend througha corresponding side slot 314 in the articulation member 300. A thrustattachment feature 432 may be formed on the distal end of each distalplate portion 430 to retain the distal plate portion 430 within itsrespective side slot 314. In alternative embodiments, the thrust featuremay be molded into the articulation member 300 or other attachmentarrangements may be used. Articulation link 256R, 256L may further havean elongated extension portion 334R, 334L that terminates in a hookportion 336R, 336L, respectively. In various embodiments, thearticulation links 256R, 256L may be fabricated from metal or a seriesof laminated or stacked plates.

Referring to FIG. 104, there is shown a control rod assembly 125′ thatmay be substantially similar to control rod assembly 125 describedabove, except that control rod assembly 125′ includes a rightarticulation link 123R and a left articulation link 123L. The rightarticulation link 123R may have a distal hook 165R formed thereon fordetachable engagement with the hook portion 336R of the articulationlink 256R in the disposable loading unit 3016″. See FIG. 103. Likewise,the left articulation link 123L may have a distal hook portion 165Lformed thereon for detachable engagement with the hook portion 336L ofthe articulation link 256L in the disposable loading unit 3016″. Theright articulation link 123R may further have a finger 164R protrudingfrom its proximal end, and the left articulation link 123L may have afinger 164L protruding from its proximal end. Although not specificallyillustrated in FIG. 103, a linkage bar, gear train, etc. may be employedto movably couple the fingers 164R, 164L to the arm 160 attached to thetranslation member 138′ such that as the translation member 138′ isaxially advanced in the distal “DD” direction as described in detailabove, the right articulation links 123R and 256R are advanced in thedistal direction “DD” and the left articulation links 123L and 256L arepulled in the proximal direction “PD” to thereby cause the tool assembly17 to pivot about the first articulation axis “A1-A1” to the right ofthe longitudinal axis L-L as illustrated in FIG. 101 or visa-versa.Likewise, in various embodiments, when the translation member 138′ isadvanced in the proximal direction “PD”, the right articulation links123R and 256R are pulled in the proximal direction “PD” and the leftarticulation links 123L and 256L are advanced in the distal direction“DD” to thereby cause the tool assembly 17 to pivot to the left of thelongitudinal axis L-L or visa-versa. Those of ordinary skill in the artwill understand that such “pushing” and “pulling” action results in lessstresses being applied to a single articulation link than those priorarticulation arrangements that only employ a single articulation link.The flexible articulation member 300′ may require more force to bend orflex as opposed to the pivot pin arrangement like in 206.

FIGS. 105-107 illustrate another reload unit 3016′″ embodiment of thepresent invention. Reload unit 3016′″ is essentially a combination ofreload units 3016 and 3016′ in that reload unit 3016′″ employs thearticulation link 256′ and the articulation links 256R and 256L thatenables the articulation link 300′ to be passively articulated through arange of travel “PA” and actively articulated through an additionalrange of travel “AA”.

FIGS. 108-111 illustrate another surgical stapling apparatus 4010 of thepresent invention that is constructed for use with a disposable loadingunit. FIG. 108 depicts a disposable loading unit 16 that has a firstarticulation joint 340 of the type and construction described above thatenables the tool assembly 17 to pivot about a first pivot axis A1-A1relative to the disposable loading unit housing 200 that is attached tothe surgical stapling apparatus 4010. The surgical stapling apparatus4010 may have aspects and components that are substantially similar tothe aspects and components of the various stapling apparatus embodimentsdescribed above, except for the unique and novel articulation system4012, various configurations of which, will be described in detailbelow. Those components that are the same as the components employed inthe above-mentioned surgical stapling apparatus embodiments will belabeled with the same element numbers and those of ordinary skill in theart can refer to the disclosure set forth hereinabove that explainstheir construction and operation. As can be seen in FIG. 108, thearticulation system 4012 may include an intermediate articulation joint4020 that is situated in the elongated body assembly 4014 between thedisposable loading unit 16 and the handle assembly 12 such that thedisposable loading unit 16 may be selectively pivoted relative to thehandle assembly 12 about a second articulation axis A2-A2. Asillustrated in FIG. 108, the second articulation axis A2-A2 issubstantially transverse to the longitudinal axis L-L and the firstarticulation axis A1-A1.

As can be seen in FIGS. 108 and 109, the elongated body assembly 4014may comprise a distal body segment 4030 and a proximal body segment 4040that are coupled together at the intermediate articulation joint 4020.The articulation system 4012 may further include a translation member138 that has an upstanding arm portion 540 that has a notch 542 thereinthat is sized to receive a tab 544 formed on the sensor cylinder 178.The distal end of translation member 138 may include an arm 546 whichincludes an opening 548 configured to receive a finger 164 extendingfrom the proximal end of articulation link 4050. A pin 166 that may beconstructed from a non-abrasive material, e.g., Teflon® or metal coatedwith Teflon®, is secured to translation member 138 and dimensioned to bereceived within stepped camming surface 148 (shown in FIG. 11). Theoperation of those components was described above.

FIG. 110 illustrates an intermediate articulation joint embodiment 4020of the present invention. As can be seen in that Figure, the distal bodysegment 4030 is hollow and has a proximal end 4031 that has twoproximally protruding lugs 4032 formed thereon. Each lug 4032 may have apin 4034 protruding therefrom and at least one locking rib 4036 formedthereon. The proximal body segment 4040 is hollow and, as can be seen inFIG. 109, has a proximal end 4041 that has openings 128 for receiving acorresponding radial projection 132 (shown in FIG. 10) formed on therotatable knob 28 as was described above. As can be seen in FIG. 110,the distal end 4042 of the proximal body segment 4040, may have a pairof distally protruding lugs 4044 that each have a pin receiving hole4046 therethrough for receiving a corresponding pin 4034 on the distalbody segment 4030 to enable the distal body segment 4030 to pivotrelative to the proximal body segment 4040. Each lug 4044 may have aseries of radial grooves 4048 formed thereon to mesh in confrontingengagement with the corresponding locking ribs 4036 on the lugs 4032.Thus, when assembled together, the pins 4034 and holes 4046 serve todefine the second articulation axis A2-A2 and are loosely fitted toenable the distal body segment 4030 to be pivoted to a desired positionrelative to the proximal body segment 4040 by applying a force to thedistal body segment 4030 while keeping the proximal body segment 4040stationary or visa-versa. The interaction between the locking ribs 4036and the grooves 4048 serve to retain the distal body segment 4030 in thedesired position relative to the proximal body segment 4040 after thearticulation force has been discontinued. In alternative embodiments,the locking ribs 4036 may be formed on the distally protruding lugs 4044and the radial grooves 4048 may be formed on the proximally protrudinglugs 4032. In still other embodiments, at least one locking rib 4036 maybe formed on one lug 4032 and radial grooves 4048 may be provided on thelug 4044 attached thereto and at least one locking rib 4036 may beprovided on the other lug 4044 and the grooves 4048 provided on the lug4032 attached to that lug 4044. When coupled together by theintermediate articulation joint 4020, the distal body segment 4030 andthe proximal body segment 4040 of the elongated body assembly 4014define the longitudinal axis L-L.

As indicated above, the articulation system 4012 may further comprise anarticulation link 4050 that includes a proximal portion 4052 that has afinger 164 protruding therefrom that is configured to be received in theopening 548 in the arm 546 of the translation member 138. See FIG. 109.The articulation link 4050 may further have a distal portion 4054 thatis pivotally pinned to the proximal portion 4052 such that the distalportion 4054 can pivot relative to the proximal portion 4052 about anarticulation axis A2′-A2′. The distal end of the distal portion 4054 hasa distal hook 165 formed thereon for detachable engagement with the hookportion of the articulation link in the disposable loading unit 16 in aknown manner. As can also be seen in FIG. 109, this embodiment mayemploy a hollow sensor tube 4060 that has a distal portion 4062 that ispivotally coupled to a proximal portion 4064 for pivotal travel relativethereto about an articulation axis A2″-A2″. The distal portion 4062 andthe proximal portion 4064 of the sensor tube 4060 may be loosely coupledtogether to enable the sensor tube 4060 to accommodate some axialmisalignment of components. For example, in various embodiments, thesensor tube portions 4062 and 4064 may be coupled to permit a ±0.125″axial movement of those components relative to each other. The sensortube 4060 may operate in the same way as was described above withrespect to sensor tube 123 and may have a control rod locking mechanism(not shown) of the type described above attached thereto.

As can also be seen in FIG. 109, the articulation system 4012 mayinclude a control rod assembly 4070 that is similar in operation tocontrol rod 52 above, except for the articulation segment 4074 thatinterconnects a distal portion 4072 and a proximal portion 4076. Thearticulation segment 4074 may comprise a series of laminated metalstrips that will enable the control rod assembly 4070 to bend as theelongated body assembly 4014 is articulated about the intermediatearticulation joint 4042, yet be sufficiently stiff to axially transmitthe firing forces from the handle assembly 12 to the disposable loadingunit 16. Other flexible joint arrangements could also be employed. Inaddition, an O-ring 4080 may be provided between the proximal portion4076 of the control rod assembly 4070 and the sensor tube 4060 toprovide additional support to the control rod assembly 4070 therein.When assembled together, those of ordinary skill in the art willappreciate that the articulation link 4050 and the sensor tube 4060 aresupported within the elongated body assembly 4014 such that the axesA2″-A2″ and A2′-A2′ substantially coincide with the second articulationaxis A2-A2. Likewise, the control rod assembly 4070 is supported withinthe elongated body assembly 4014 such that the articulation segment 4074spans the intermediate articulation joint 4020.

FIG. 111 depicts use of the surgical stapling apparatus 4010 in an“open” surgery setting wherein the disposable loading unit 16 andelongated body assembly 4014 are inserted into the patient through anopen incision in the tissue “T”. As can be understood from reference tothat Figure, the tool assembly 17 may be selectively articulated aboutthe first articulation axis A1-A1 by manipulating the articulation lever30 as was described above. The disposable loading unit 16 may also bepivoted about the second articulation axis A2-A2 relative to theproximal body segment 4040 of the elongated body assembly 4014 andhandle assembly 12 by “passively” bringing the tool assembly 17 intocontact with the organ or other portion of the body or by grasping thedisposable reload unit 16 with another surgical instruments such as, forexample, graspers (not shown) to apply an external force to the toolassembly 17 to cause it to articulate about the second articulation axisA2-A2. The person of ordinary skill in the art will appreciate that oncethe tool assembly 17 is articulated to the desired position about thesecond articulation axis A2-A2, it is retained in that position byvirtue of the engagement between the locking ribs 4036 and radialgrooves 4048 as described above. To enable the stapling apparatus 4010to be used endoscopically through a conventional trocar 4000 as shown inFIG. 112, the intermediate articulation joint 4020 may be providedadjacent the rotation knob 28 such that the articulation joint 4020 canremain external to the trocar 4000 to enable the handle assembly 12 tobe pivoted about the second articulation axis A2-A2, relative to theportion of the surgical stapling apparatus 4010 protruding into thepatient through the trocar 4000.

FIGS. 113-115 illustrate an articulation system 5012 that may beemployed with various surgical stapling apparatuses of the presentinvention. Those components that are the same as the components employedin the above-mentioned embodiments will be labeled with the same elementnumbers and those of ordinary skill in the art can refer to thedisclosure set forth hereinabove that explains their construction andoperation. The articulation system 5012 may include an intermediatearticulation joint 5020 in the elongated body assembly 5014 thatfacilitates pivotal travel of the disposable reload unit 16 relative tothe handle assembly 12 about a second articulation axis A2-A2 that issubstantially transverse to the longitudinal axis L-L and the firstarticulation axis A1-A1. The elongated body assembly 5014 may comprise adistal body segment 5030 and a proximal body segment 5040 that arecoupled together at the intermediate articulation joint 5020. As shownin FIG. 114, the articulation system 5012 may further include atranslation member 138 that has an upstanding arm portion 540 that has anotch 542 therein that is sized to receive a tab 544 formed on thesensor cylinder 178. The distal end of translation member 138 mayinclude an arm 546 which includes an opening 548 configured to receive afinger 164 extending from the proximal end of articulation link 4050. Apin 166 that may be constructed from a non-abrasive material, e.g.,Teflon® or metal coated with Teflon® is secured to translation member138 and dimensioned to be received within stepped camming surface 148(shown in FIG. 11). The operation of these components was describedabove.

As further shown in FIG. 114, the distal body segment 5030 is hollow andhas a proximal end 5031 that has two proximally protruding lugs 5032.Each lug 5032 has a pin 5034 protruding therefrom. The proximal bodysegment 5040 is hollow and has an opening 128 for receiving acorresponding radial projection 132 formed on the rotatable knob 28 aswas described above. See FIGS. 114 and 115. The distal end 5042 of theproximal body segment 5040 may have a pair of distally protruding lugs5044 that each have a pin receiving hole (not shown) therethrough forreceiving a corresponding pin 5034 on the distal body segment 5030, toenable the distal body segment 5030 to pivot relative to the proximalbody segment 5040. In various embodiments, the intermediate articulationjoint 5020 may be formed with the radial grooves 4048 and locking ribs4036 as was described above. The intermediate articulation joint 5020 inother embodiments may be made without such radial grooves and lockingribs.

The articulation system 5012 illustrated in FIGS. 113-115 is an “active”articulation system and may include an articulation bar 5050 that has adistal end 5052 that is pinned or otherwise attached to the distal bodysegment 5030 by a pin 5054. As shown in FIG. 114, the articulation bar5050 may ride in an elongated bar slot 5043 provided in the proximalbody segment 5040 of the elongated body assembly 5014. To provideadditional support to the articulation bar 5050, a shroud 5080 may beplaced over the proximal body segment 5040. See FIGS. 113 and 115. Thearticulation bar 5050 may have a proximal end 5056 that is integrallyformed with or otherwise non-movably attached to a stabilizing collar5060. The stabilizing collar 5060 may be sized to fit about the proximalbody segment 5040 and have a base portion 5062 attached thereto that isattached to or formed with a button post 5064 that terminates in anarticulation button 5066. As can be seen in FIGS. 114 and 115, the baseportion 5062 may be formed with two upwardly extending lock detents 5068that are adapted to retainingly engage locking racks 5072 formed on twolocking plates 5070 that are non-movably supported in the rotation knob28. As shown in FIGS. 114 and 115, two locking plates 5070 may beemployed—one on each side of the button post 5064.

Referring to FIG. 113, to articulate the distal body segment 5030 aswell as the distal portion 4072 of the control rod assembly 4070 (andthe disposable loading unit attached thereto) in the right direction“RD” about the second articulation axis A2-A2, the clinician simplyslides the articulation button 5066 in the distal “D-D’ direction. Toarticulate the distal body segment 5030, distal portion 4072 of thecontrol rod assembly 4070 and the disposable loading unit in the leftdirection “LD”, the clinician slides the articulation button 5066 in theproximal direction “PD”. Those of ordinary skill in the art willunderstand that the articulation system 5020 may be effectively employedwith surgical stapling apparatuses that are adapted to receivearticulatable and non-articulatable disposable reload units. Thearticulation system 5012 depicted in FIGS. 113-115 is well adapted foruse in open surgical applications. The articulation system 5012′depicted in FIG. 116 may be better suited for endoscopic applications.As can be seen in that Figure, the articulation joint 5020 is closer tothe rotation knob 28 such that when in use, the articulation joint 5020is external to the trocar through which the distal body segment 5030 ofthe elongated body assembly 5014 extends.

FIGS. 117-121 illustrate a unique and novel “active” articulation system6012 that may be used in connection with various surgical staplingapparatuses adapted for use with disposable loading units. Thosecomponents of the articulation system 6012 that are the same as thecomponents employed in the above-mentioned embodiments will be labeledwith the same element numbers and those of ordinary skill in the art canrefer to the disclosure set forth hereinabove that explains theirconstruction and operation. In various embodiments, the articulationsystem 6012 includes a rotation knob assembly 6028 that, except for thedifferences noted below, is similar to rotation knob 28 described above.As can be seen in FIG. 118, the rotation knob 6028 has an articulationshroud extension 6030 that has a distal articulation ball 6032 formedthereon. In various embodiments, the rotation knob assembly 6028 may beformed from two segments 6028 a and 6028 b that are molded from plasticor other suitable material and which may be interconnected by, forexample, snap features, screws, adhesive, etc. See FIG. 117. Rotatablyreceived on the distal articulation ball 6032 is a distal body segment6040 whose proximal end 6042 forms an articulation socket 6044 that maybe formed from cover segments 6040 a and 6040 b that may beinterconnected by snap features, adhesive, etc. As illustrated in FIG.118, the articulation system 6012 may also include a translation memberof the type and construction described above which is configured toreceive a finger 164 extending from the proximal end of articulationlink 4050′. Articulation link 4050′ is similar to articulation link 4050described above except that the articulation link 4050′ has a flexibleconnector portion (coil spring, etc.) 6025 formed therein.

As can be seen in FIG. 118, the articulation system 6012 may furthercomprise a hollow sensor tube 6060 that has a distal portion end 6062that is coupled to a proximal portion 6064 by a flexible connector (coilspring, etc.) 6066. The sensor tube 6060 may operate in the same way aswas described above with respect to sensor tube 123 and may have acontrol rod locking mechanism (not shown) of the type described aboveattached thereto. As can also be seen in FIG. 118, the articulationsystem 6012 may include a control rod assembly 6070 that is similar inoperation to control rod 52 above, except for the flexible connectorsegment 6074 that interconnects a distal portion 6072 and a proximalportion 6076. The flexible connector segment 6074 may comprise a coilspring, etc. that will enable the control rod assembly 6070 to bendduring articulation, yet be sufficiently stiff to axially transmit thefiring forces from the handle assembly 12 to the disposable loading unit16. As can be seen in FIGS. 118 and 119, the control rod assembly 6070extends through the sensor tube 6060 and the proximal end portion 6076is supported therein by an O-ring 6068. To provide additional axialsupport to the proximal portion 6076 of the control rod assembly 6070and the flexible connector segment 6074, a proximal firing rod tube 6080may be employed. See FIGS. 118 and 119. When assembled together, thoseof ordinary skill in the art will appreciate that the flex connectorportion 6025 of articulation link 4050′, flexible connector portion 6066of the sensor tube 6060 and the flexible connector segment 6074 aresupported within the articulation ball 6032 as shown in FIG. 119.

As can be seen in FIGS. 118 and 119, the articulation system 6012further comprises a articulation handle 6090 that is movably supportedon the distal end 6034 of the shroud extension 6030. In variousembodiments, the articulation handle 6090 may be formed from two arcuatesegments 6090 a and 6090 b that are coupled together, by, for example,screws 6091 or other suitable fastener arrangements. The articulationhandle 6090 is coupled to two diametrically opposed horizontalarticulation bands 6100 and two diametrically opposed verticalarticulation bands 6110. See FIG. 118. referring now to FIGS. 120 and121, in various embodiments, the proximal end 6102 of each horizontalarticulation band 6100 may be pivotally coupled to a horizontalarticulation pin 6104. Likewise the proximal end 6112 of each verticalarticulation band 6110 may be pivotally coupled to a verticalarticulation pin 6114. FIGS. 120 and 121, illustrate one form ofattaching the proximal end 6102 of a horizontal articulation band 6100to a horizontal articulation pin 6104 as well as of attaching theproximal end 6112 of a vertical articulation band 6110 to a verticalarticulation pin 6114. As can be seen in those Figures, a ball connector6120 may be coupled to the distal ends 6102, 6112 and be rotatablyreceived in a corresponding socket 6108, 6118 in the horizontal andvertical articulation pins 6104, 6114, respectively. The horizontalarticulation pins 6104 may extend through diametrically opposedhorizontal slots 6036 (FIG. 118) in the proximal end portion 6034 of theshroud extension 6030 to be received in holes 6092 in the articulationhandle 6090. Similarly, the vertical articulation pins 6114 extendthrough vertical slots 6038 formed in the proximal end portion 6034 ofthe shroud extension 6030 to be received in holes 6094 in thearticulation ring 6090.

In various embodiments, the horizontal articulation bands 6100 and thevertical articulation bands 6110 may comprise metal bands that will bendor flex about their weak axis (i.e., the axis that extends transverselyto their length), but will not bend or flex in their strong axis (i.e.,their elongated axis extending along their length). To provide supportto the articulation bands 6100, 6110 along their respective lengths, thehorizontal articulation bands 6100 may be movably supported in elongatedhorizontal slots 6033 formed in the elongated shroud 6030. The distalend 6106 of each horizontal articulation band 6100 may have a distalarticulation pin 6109 protruding therefrom that extends through acorresponding horizontal slot 6037 in the ball portion 6032 of theelongated shroud 6030 to be coupled to the distal body segment 6040. Invarious embodiments, the distal articulation pin 6109 extends through ahole in the corresponding distal end 6106 of the horizontal articulationband 6100 to enable the distal end 6106 thereof to rotate there around.Similarly, the distal end 6116 of each vertical articulation band 6110may have a distal articulation pin 6119 protruding therefrom thatextends through a corresponding vertical slot 6039 in the ball portion6032 of the elongated shroud 6030 to be coupled to the distal bodysegment 6040. See FIG. 119. The distal articulation pins 6119 may extendthrough a hole in the distal end 6116 of a corresponding verticalarticulation band 6110 to enable the distal end 6116 to rotatetherearound.

Although not specifically illustrated in FIGS. 117-118, those ofordinary skill in the art will understand that the distal body segment6040 may be configured for operable attachment to an articulatabledisposable loading unit or a non-articulatable disposable loading unitin the manner described above or in the manner that is known in the art.However, in this embodiment, the clinician can selectively articulatethe distal body segment 6040 and the disposable loading unit attachedthereto by selectively pivoting the articulation handle 6090 on theproximal end 6034 of the shroud extension 6030. For example, FIG. 119illustrates the articulation handle 6090 pivoted to a position whereinthe distal body segment 6040 is pivoted in the vertical direction “VD”.To pivot the distal body segment 6040 in a horizontal direction (thedirection perpendicular to the direction VD depicted in FIG. 119), theclinician first brings the articulation handle back to a verticalneutral position (wherein the distal body segment 6040 is coaxial withthe shroud extension 6030 and then the clinician pivots the articulationhandle such that one side portion of the handle 6090 moves in the distaldirection, while the other side moves in the proximal direction(represented by arrows “DD” and “PD” in FIG. 117). Such activearticulation comprises substantially bi-planar articulation. That is,the distal body segment 6040 and the disposable loading unit coupledthereto can only be selectively articulated through a verticallyextending plane or through a horizontally extending plane that issubstantially orthogonal to the vertically extending plane. The distalbody segment 6040 and the disposable loading unit cannot be articulatedin the vertical and horizontal directions at the same time. However,those of ordinary skill in the art will appreciate that the rotationknob 6028 by virtue of its rotatable attachment to the handle assemblyfacilitates selective rotation of the distal body segment 6040 and thedisposable loading unit coupled thereto about the longitudinal axis L-L.

FIGS. 122 and 123 illustrate another surgical stapling apparatusembodiment 7010 of the present invention that employs a passivearticulation system 7012. As can be seen in those Figures, the passivearticulation system 7012 may comprise a rotation knob 7028 that issomewhat similar to rotation knob 28 described above, except for thedifferences discussed below. Those components of the surgical staplingapparatus 7010 that are the same as the components employed in theabove-mentioned embodiments will be labeled with the same elementnumbers and those of ordinary skill in the art can refer to thedisclosure set forth hereinabove that explains their construction andoperation. As can be seen in FIG. 123, the rotation knob 7028 has anarticulation socket 7030 formed therein that is sized to rotatablyreceive a ball 7016 formed on an elongated body assembly 7014. Inalternative embodiments, the socket 7030 may be formed in a casingsegment that is non-rotatably supported within the rotatable knob 7028.The distal end 7015 of the elongated body assembly 7014 is configuredfor operable attachment to an articulatable or non-articulatabledisposable loading unit in a known manner. As can also be seen in FIG.123, the articulation system 7012 may further include a translationmember 138 that has an upstanding arm portion 540 that has a notch 542therein that is sized to receive a tab (not shown) formed on the sensorcylinder (not shown) in the manner described above. The distal end oftranslation member 138 may include an arm 546 which includes an opening548 configured to receive a finger 164 extending from the proximal end7052 of articulation link 7050. The distal end 7054 of the articulationlink 7050 has a distal hook 165 formed thereon which can hookinglyengage an articulation tab or hook formed on an articulation linksupported in the disposable reload unit. A pin 166 that may beconstructed from a non-abrasive material, e.g., Teflon® or metal coatedwith Teflon®, is secured to translation member 1318 and dimensioned tobe received within stepped camming surface 148 (shown in FIG. 11). Ascan be seen in FIG. 123, a flexible member 7055 in the form of a coilspring or the like may be provided in the articulation link 7050adjacent the proximal end 7052 thereof.

The passive articulation system 7012 may further comprise a hollowsensor tube 7060 that has a distal portion end 7062 that is coupled to aproximal portion 7064 by a flexible connector (coil spring, etc.) 7066.The sensor tube 7060 may operate in the same way as was described abovewith respect to sensor tube 123 and may have a control rod lockingmechanism (not shown) of the type described above attached thereto. Ascan also be seen in FIG. 123, the articulation system 7012 may include acontrol rod assembly 7070 that is similar in operation to control rod 52above, except for the flexible connector segment 7074 that interconnectsa distal portion 7072 and a proximal portion 7076. The flexibleconnector segment 7074 may comprise a coil spring, etc. that will enablethe control rod assembly 7070 to bend during articulation, yet besufficiently stiff to axially transmit the firing forces from the handleassembly 12 to the disposable reload unit 16. The firing rod assembly7070 extends through the sensor tube 7060 and the distal portion 7072 issupported therein by an O-ring 7068. When assembled together, those ofordinary skill in the art will appreciate that the flex connectorportion 7055 of articulation link 7050, flexible connector portion 7066of the sensor tube 7060 and the flexible connector segment 7074 of thecontrol rod assembly 7070 are at least partially supported within thearticulation ball 7016 and socket 7030.

FIG. 122 illustrates use of the surgical stapling apparatus 7010 of thepresent invention with a conventional trocar 4000. As can be seen inthat Figure, a disposable loading unit 16 is coupled to the elongatedbody assembly 7014. Although an articulatable disposable loading unit 16is illustrated, the person of ordinary skill in the art will understandthat the apparatus 7012 may be effectively employed withnon-articulating disposable loading units. After the trocar 4000 hasbeen installed through the tissue “T” utilizing known techniques, theclinician can insert the disposable loading unit 16 through the trocarinto the patient. If an articulatable disposable loading unit 16 isemployed, the clinician must orient the disposable loading unit in anon-articulated state to insert it through the trocar. After thedisposable loading unit 16 has been inserted into the patient andactuated to clamp onto the target tissue in the manners described above,the clinician may articulate the handle simply by pivoting the handleassembly 12 about the ball and socket articulation joint 7020. The ballportion 7016 may be sized relative to the socket 7030 such that asufficient amount of friction is established between the components atrest to retain them in position, yet not be so great as to preventmanipulation of those components relative to each other. In otherembodiments, detents may be provided in the ball and socket jointcomponents to retain the joint in various positions. The clinician mayalso manipulate the handle assembly 12 relative to the elongated bodyassembly 7014 prior to clamping onto the target tissue by grasping theproximal end of the elongated body assembly protruding from the trocar4000 and then manipulating the handle assembly 12 relative thereto.

While several embodiments of the invention have been described, itshould be apparent, however, that various modifications, alterations andadaptations to those embodiments may occur to persons skilled in the artwith the attainment of some or all of the advantages of the invention.For example, according to various embodiments, a single component may bereplaced by multiple components, and multiple components may be replacedby a single component, to perform a given function or functions. Thisapplication is therefore intended to cover all such modifications,alterations and adaptations without departing from the scope and spiritof the disclosed invention as defined by the appended claims.

The devices disclosed herein can be designed to be disposed of after asingle use, or they can be designed to be used multiple times. In eithercase, however, the device may be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, the devicemay be disassembled, and any number of particular pieces or parts of thedevice can be selectively replaced or removed in any combination. Uponcleaning and/or replacement of particular parts, the device may bereassembled for subsequent use either at a reconditioning facility, orby a surgical team immediately prior to a surgical procedure. Those ofordinary skill in the art will appreciate that the reconditioning of adevice may utilize a variety of different techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of the presentapplication.

Preferably, the invention described herein will be processed beforesurgery. First a new or used instrument is obtained and, if necessary,cleaned. The instrument can then be sterilized. In one sterilizationtechnique, the instrument is placed in a closed and sealed container,such as a plastic or TYVEK® bag. The container and instrument are thenplaced in a field of radiation that can penetrate the container, such asgamma radiation, x-rays, or higher energy electrons. The radiation killsbacteria on the instrument and in the container. The sterilizedinstrument can then be stored in the sterile container. The sealedcontainer keeps the instrument sterile until it is opened in the medicalfacility.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

The invention which is intended to be protected is not to be construedas limited to the particular embodiments disclosed. The embodiments aretherefore to be regarded as illustrative rather than restrictive.Variations and changes may be made by others without departing from thespirit of the present invention. Accordingly, it is expressly intendedthat all such equivalents, variations and changes which fall within thespirit and scope of the present invention as defined in the claims beembraced thereby.

1. A surgical stapling apparatus, comprising: a handle assembly including a movable handle and a stationary handle housing, the movable handle being movable through actuation strokes relative to said stationary handle housing; an actuation shaft supported at least in part within said stationary handle housing and mounted for longitudinal movement in response to manipulation of said movable handle through said actuation strokes; a control rod assembly having a proximal end interfacing with said actuation shaft, said control rod assembly protruding distally from said handle housing and having a distal end configured to be operably attached to a disposable loading unit; a firing lock out assembly supported at least in part within said stationary handle housing and configured to selectively prevent longitudinal movement of said actuation shaft in a distal direction; and a firing release trigger supported on said movable handle for travel therewith and interfacing with said firing lockout assembly to selectively release said firing lockout assembly to permit said actuation shaft to move longitudinally in said distal direction upon manipulation of said movable handle.
 2. The surgical stapling apparatus of claim 1 wherein said movable handle and said firing release trigger can be simultaneously actuated by a single hand.
 3. The surgical stapling apparatus of claim 1 wherein said firing lock out assembly comprises a locking gate movably supported by said handle housing, said locking gate communicating with said firing release trigger and being selectively movable between a first position wherein said locking gate engages said actuation shaft to prevent longitudinal movement thereof and disengaged positions in response to actuation of said firing release trigger.
 4. The surgical stapling apparatus of claim 3 further comprising a linkage assembly operably interfacing with said release trigger and said locking gate.
 5. The surgical stapling apparatus of claim 4 wherein said linkage assembly comprises: a gate gear operably supported by said handle housing, said gate gear having gate gear teeth thereon in meshing engagement with a gear rack on said locking gate; a release pawl operably supported by said handle assembly and being linked to said gate gear to selectively apply actuation motions to said gate gear; and a first gear operably supported by said handle housing and linked to said release pawl, said first gear having at least some first gear teeth thereon configured to be engaged by release gear teeth on said firing release trigger when said firing release trigger is actuated such that when said firing release trigger is actuated, said first gear transfers an actuation motion to said release pawl which, in turn, transmits another actuation motion to said gate gear which, in turn, actuates said locking gate.
 6. The surgical stapling apparatus of claim 3 wherein said firing release trigger is coupled to a flexible actuation member supported within said handle housing for transmitting actuation motions from said firing release trigger to said locking gate.
 7. The surgical stapling apparatus of claim 6 further comprising a gate gear operably supported by said handle housing, said gate gear having gate gear teeth thereon in meshing engagement with a gear rack on said locking gate, said gate gear communicating with said flexible actuation member to receive said at least one actuation motion from said firing release trigger.
 8. The surgical stapling apparatus of claim 7 further comprising a linkage member coupled to said gate gear and interfacing with said flexible actuation member to transfer said at least one actuation motion from said flexible actuation member to said gate gear.
 9. A method for processing an instrument for surgery, the method comprising: obtaining the surgical stapling apparatus of claim 1; sterilizing the surgical stapling apparatus; and storing the surgical stapling apparatus in a sterile container.
 10. The method of claim 9 further comprising repairing or replacing a portion of said surgical stapling apparatus prior to said sterilizing.
 11. A method for processing an instrument for surgery, the method comprising: obtaining the surgical stapling apparatus of claim 6; sterilizing the surgical stapling apparatus; and storing the surgical stapling apparatus in a sterile container.
 12. The method of claim 11 further comprising repairing or replacing a portion of said surgical stapling apparatus, prior to said sterilizing.
 13. A surgical stapling apparatus, comprising: a handle assembly including a movable handle and a stationary handle housing, the movable handle being movable through actuation strokes relative to said stationary handle housing; an elongated body extending distally from the handle assembly and having a distal end adapted to releasably engage both articulating and non-articulating disposable loading units and transmit actuation motions thereto; an actuation member supported in said stationary handle housing and configured to apply a said actuation motion to said elongated body in response to manipulation of said movable handle through said actuation strokes; a firing lock out assembly supported at least in part within said stationary handle housing and configured to selectively prevent longitudinal movement of said actuation shaft in a distal direction; and a firing release trigger supported on said movable handle for travel therewith and interfacing with said firing lockout assembly to selectively release said firing lockout assembly to generate said actuation motions upon manipulation of said movable handle.
 14. The surgical stapling apparatus of claim 13 wherein said movable handle and said firing release trigger can be simultaneously actuated by a single hand.
 15. The surgical stapling apparatus of claim 14 wherein said firing release trigger is configured to be actuated by pulling the firing release trigger toward a portion of the movable handle.
 16. A method for processing an instrument for surgery, the method comprising: obtaining the surgical stapling apparatus of claim 13; sterilizing the surgical stapling apparatus; and storing the surgical stapling apparatus in a sterile container.
 17. The method of claim 16 further comprising repairing or replacing a portion of said surgical stapling apparatus, prior to said sterilizing.
 18. A surgical stapling apparatus, comprising: a handle assembly including a movable handle and a stationary handle housing, the movable handle being movable through actuation strokes relative to said stationary handle housing; actuation means supported in said handle assembly for generating actuation motions in response to manipulation of said movable handle; control means interfacing with said actuation means for transferring said actuation motions to a disposable loading unit operably coupled thereto; means for selectively preventing said actuation means from generating said actuation motions; and trigger means on said movable handle for controlling said means for selectively preventing.
 19. A method of operating a surgical instrument, said method comprising: providing a surgical stapling apparatus of claim 1; operably coupling a disposable loading unit to the surgical stapling apparatus; manipulating the movable handle to clamp tissue with the disposable loading unit; actuating the firing release trigger; and manipulating the movable handle to cause the actuation shaft to move distally in the stationary handle housing and apply actuation motions to the control rod assembly.
 20. The method of claim 19 wherein said operably coupling comprises operably coupling an articulatable disposable loading unit to the surgical stapling apparatus.
 21. A method of operating a surgical instrument, said method comprising: providing a surgical stapling apparatus of claim 13; operably coupling a disposable loading unit to the surgical stapling apparatus; manipulating the movable handle to clamp tissue with the disposable loading unit; actuating the firing release trigger; and manipulating the movable handle to cause the actuation shaft to move distally in the stationary handle housing and apply actuation motions to the control rod assembly.
 22. The method of claim 21 wherein said operably coupling comprises operably coupling an articulatable disposable loading unit to the surgical stapling apparatus. 